Wednesday, September 13, 2017

The Eyes Have it - Chatoyant minerals



 As a lapidarian, my favorite chatoyant stones to work with are pietersite and tiger eye. They both provide a lot of flash, especially in cabochon form and they're not as picky about angles as I've found laboradite to be. They also both take a nice polish which adds to the flash of the chatoyance.

One of the reasons I love working with pietersite is the way the waves of parallel fibers fold back and forth over themselves, creating unique patterns like on this blue specimen. The material is pricey, but I love to treat myself to a piece now and then. Wouldn't you?



 A BEAUTIFUL WORD FROM THE FRENCH!

Chatoyance (Sha-toy-ance) is a delightful word that rolls off the tongue. It comes from the French word chatoyer, meaning shine or luster. It's probably no accident that the first four letters "chat" mean cat in French and the cats eye effect in minerals is called chatoyant. You'll hear a lot of rockhounds and lapidary artists refer to it as the 'flash' in the stone, because it only shows that remarkable shine when the light hits it just right


This beautiful reddish tiger eye is nothing to look at  in normal light, but put it in the sun and you get flashes of light called chatoyance. Tiger Eye is one of many stones that share this characteristic.  Chatoyance occurs when fibers in a stone line up parallel to each other, at least in a segment. The shine/flash is always perpendicular to the fibers.




This tiger eye that was in a different blog posting. I love the way it demonstrates how bright the flashes can be.              






 IT'S ALL ABOUT THE LIGHT!

This not very attractive stone is a slab of labradorite I photographed in indirect light. You can see there are some different colors, but it's not anything to get excited about.

However, you can see the same stone below photographed in sunlight, and the chatoyance creates flashes of dramatic colors. The secret to working with it is to be sure to get that flash on the face of the cabochon. I see it used a lot by wire work artists where the shine of the silver adds to the effect.

Charoite is listed as a chatoyant mineral, and I've seen some that is, but this cab of mine really isn't. Part of the problem is that not all charoite has bands of parallel fibers. Since the flash happens when the fibers are not parallel to the base and these fibers are completely disorganized, it doesn't flash at all for me.

At the same time, it is still a gorgeous purple cab and the white fibers add a lot of interest.





Have you ever made cabs with chatoyant minerals?  I'd love to see some pictures of you work!

Until next time,
Your Lapidary Whisperer,

Donna




Wednesday, August 30, 2017

YOU CAN BRING MONTANA BEAUTY HOME! CHECK THIS OUT!


 I love Montana Agate both for its distinctive style and at about 6.5-7 on the Mohs scale, it's a delight to work and polishes beautifully.

And even though it is very distinctive, there are enough variations in the inclusions to allow the lapidary to come up with countless wonderful stories contained in these stones. This one makes me think of a fast-moving stream going over a gravel bed. The creamy agate is separating the gravel except for one thin area that is fighting the water's power.

These beautiful stones are found in Montana, specifically the gravel areas between Billings and Sidney. They got there courtesy of the Yellowstone River which transported them from the Yellowstone Park area of Wyoming where they formed in volcanic during the Pleistocene Age which was about 12,000 to 1.8 million years ago.

 

 

MY FIRST SIGHTING

I fell in love with these stones at first glance. I thought maybe there were tiny bits of petroleum trapped when the stone hardened. Sounds good, right? 

After all, I'd often hear stories in Northern California that stones known as "Apache Tears" held petroleum. They sort of looked like they may have contained some because the color of the stones wasn't even, with some areas more clear and others dark. It was a great story, but it turns out that Apache Tears are obsidian, which often has variations in color. The Tears were a sort of naturally tumbled version.

So what was making those dots and lines that set Montana Agate apart?  It turns out that the inclusions are primarily made of iron and manganese oxides.The iron oxides give the inclusions a red color and the manganese oxides provide black dots and stripes. They are embedded in quartz that can range from clear to a creamy white.  Sometimes people refer to the inclusions as being mossy. They aren't, but seeing this slab makes it easy to see why some would describe it that way.

 

WORKING THE AGATE

As I mentioned, the stone has a nice 6.5-7 harness, making it hard, but not so hard it takes forever to work.

The inclusions also make it fun to try to figure out how the stone wants to be seen.  This horizontal stripe piece looks a bit like a long flag to me. The iron and manganese oxide stripes are a bit fuzzy and I think the longish wavy lines add a bit of motion to the image.

One thing I really appreciate about Montana Agate is that I've never worked a piece that broke apart, period. Even the thin bands have never given me any trouble. If you're like me, you've had absolutely gorgeous stones you've been working on that suddenly split where there was a color change, but not here!



SURPRISES!

Agate often provides some surprises and Montana Agate is no different.  On one slab, I found a druzy-lined vug that was centered between two dark spots. Since I've rarely met a vug I could resist, I decided to create a teardrop shape that emphasized the shape of the vug and allowed me to get a bit of both dark spots on the cabochon.


This little cutie was surprisingly difficult to photograph. It faded away to spots on a white background, look blue with another, and dark brown with yet another. The creamy off-white color of the agate was picking up colors from everywhere.  I finally took it outside and held it in front of a red flower, and it bloomed! You can see it picks up a bit of the red, yet most of the pure white remained pure white. I love this picture and I'll probably try this technique again.

Do you photograph your mineral specimens and cabochons? I'd love to hear how you do it. What are your secrets for a great shot?  Maybe I can include them in a future blog.

GETTING SOME FOR YOURSELF

Right now, this mineral is relatively easy to come by, either as a slab or as a finished cabochon.  I've always seen some in the rock shows along the West Coast I've made it to, and you can find it for sale online at eBay and other vendors. If you've never had a chance to work it, do get a slab and have some fun. You'll be glad you did!

Until next time, have fun with your rocks!

Your Lapidary Whisperer,

Donna





Wednesday, August 16, 2017

Story Stones II


This stone with its hidden face made me think of a burqa, a garment worn in public by some Islamic women for religious modesty.

The fact that she is hidden makes me wonder about the woman inside. Is she young or old? Thin or heavy? Is she smiling behind the light fabric covering her face? I think the pattern of brown-on-brown swirls add a bit of mystery to her.

As you can see, up around her face there are tiny voids in the st one. I've often found this material to be a bit on the soft side, and here, the inclusions of the swirls which are firmer than the matrix have caused these tiny voids during the grinding and polishing phases. I don't have a name for this jasper. I suspect that it evolved in a marine environment since the mish-mash of curves could be evidence of shells in mud.




BEACON HILL AGATE


I purchased this as part of a larger slab. There were several things that caught my eye and I saw an 'under the sea' theme right away--in an environmental way.

The darkened area consists of countless bits and having seen images of the amount of trash that has found its way to the bottom of the sea, it struck a chord with me. The rest of the slab is translucent to clear. The color it has is from a yellowish piece of paper I put behind it for the photo to highlight the druzy in the pocket of the wave going over the material.  It tells a story and is beautiful to look at. What more could I want?



JASP/AGATE



When I look at this cab I made, I think of myself sitting in an airplane and looking out the window.

Down below, I see clouds with a break in them that allows me to see the countryside with patches of greenery (farms? forests?) along with some darker areas that may be housing. In the center, there's a smooth blue-gray area that I see as a lake although in reality it's a translucent quartz. This whole mini-world takes place a one inch square cab. Amazing!





IT WAS A DARK AND STORMY NIGHT


Picasso marble is loaded with stories!  This cab is on the darker side of the Picasso I've worked. However, when I put the stencil over it, it was obviously a bad storm, like the ones you see on tv and in movies just before the ship sinks. I like to think the dark lines across the cabochon are the  mast of a venerable sailing ship and the white on the bottom is waves with the white on the top showing the reflection from the lights when I took the photo.

FOSSILS


 Some of the greatest story stones of all are fossils. They are a window into life thousands and thousands of years ago. When I purchased the slab that has this neat bug in it, I was planning to cab it, but then I took a second look in better light. He's about 1.5 inches long.

If you're having problems seeing him, the dark debris is where a collar would be and his legs are hanging down in the center of the image. I could probably cab him, but I'm afraid I'd lose parts of him in the process. Even non-lapidary people get excited when they see him!

That's all of the Story Stones for this time. I hope you enjoyed them.

Did you see the Zoo animal rocks last time? I wasn't able to get notices out on social media. Take a look at it while you're here!

Drop me a note and let me know what you saw in them.  I'll be back in two weeks with another blog.

Your Lapidary Whisperer,

Donna

Wednesday, August 2, 2017

ZOO-THEMED JASPERS

Zebra Jasper





Recently, I was looking through some slabs, and the Simon and Garfunkel lyrics, "It's all happening at the zoo," came to mind. On the table, I had slabs of zebra jasper and some beautiful tiger eye.

So I wondered, are there many other stones that could be zoo animals?  Yup! Here's the line-up of the ones I found in my shop.

The zebra is something I found at an estate sale in San Francisco. The shop equipment and contents were being sold after an old rockhound went to that lapidary shop in the sky.  I was pretty new at the hobby then, and I was entranced by the stark black vs. white coloring and the fluid lines of the rock. I took a few pounds then, now I wish I'd bought all there was.


TIGER EYE

Tiger Eye
This cab is from a smallish strip I purchased at a rock show. The first thing that struck my eye about it was how the brown intrusion on the large end drains like a lake through the most chatoyant part of the stone down to a blue tiger eye space. To me, it's a story stone, because of the way the color and the movement work together. For example, if it's not a lake draining to the bottom, what if it were a blue volcano with the brown smoke going through a bright sunset?  I believe this tiger eye originated in Western Australia where it is called Marra Mamba.

One thing I love about working tiger eye, is that with a Mohs scale hardness of 5.5-6, it is soft enough to work fairly quickly, but still hard enough to take a wonderful shine!




Snakeskin Jasper
SNAKESKIN JASPER

Okay, let's start with the fact that I have no idea why it's called snakeskin when it's red. I'm not sure I've ever seen a red snake.

The parallel red lines do remind me of a snake and I can almost see it slithering along, but really . . . Maybe it's a special zoo snake.



KAMBABA "Crocodile" JASPER

Kambaya "Crocodile" Jasper






As jasper goes, crocodile is reminiscent of the animal, but it's a long way from being the most attractive stone out there. It does give the overall impression of a crocodile skin, I haven't been able to get the cabs from the piece of rough I purchased to take much of a shine. I've been using cerium oxide on canvas. Has anyone out there had a better result with another polishing medium?


 



SHOULD BE AT THE ZOO

When you look at a piece of petoskey stone, don't you think of a tortoise shell? It really has that vibe, but I didn't see it called that anywhere. You can see images of petoskey stones at http://www.tribal-software.com 

So, these are the zoo animals from my workshop rocks. Do you have any "zoo" named minerals you're working on or any minerals you think should have zoo names?  Send me a note with a picture, I'd love to see it!

Until next time,

Your Lapidary Whisperer,
Donna

Wednesday, July 19, 2017

ROCKIN' ON THE RIVER



Let's face it, any long drive is better if you can stop for a bit and find interesting rocks. Recently, my husband and I were on our way to a lovely winery-saturated weekend in Northern California.

Now, winemaking is his thing and rocks are mine. So we decided to make both of us happy! Because we had tremendous rains last winter, a lot of fresh material has washed down to the shallower areas--a great place to check out the rocks.

I'd gotten in touch with the Contra Costa Gem & Mineral Society field trip guy, Chuck who seems to know where all the good pickings are. He recommended a place along Saint Helena Creek in Middletown, CA and we scheduled a stop there. It was right behind the parking lot of Perry's Deli (which makes delicious sandwiches and don't miss the potato salad!) and over some large rocks placed to keep you from driving into the creek.



It was 100 degrees outside when we got there for lunch. I don't do heat well, but there was a nice breeze on the water--and I was motivated.

I spent about an hour checking out rocks along the edge and just inside the shallows. I found one nice small chunk of red jasper. I'd heard that others had found it there and I was hoping to find more, but no luck. I found a variety of rocks, including some that looked like they may have dendrites, which I LOVE to work with. There were a few smaller stones that wanted me to take them home and see about tumbling them, so I did. Finally, I picked up a large, dark, smooth stone. It had dried yellow algae on the outside. I don't often choose dark stones, but this one had some small turquoise-colored inclusions and a nice heft that made me think it might be hard enough to take a shine.

HOME, HOME ON THE SAW

When I got home, I took the picture of the rocks I'd collected, then started trying to discover what I'd found.

I hoped the chunk of red jasper (center left in the picture above) with white streaks would make a couple of eye-catching cabs, so I sliced it . . .  and discovered it was not as cohesive as I'd hoped. Okay, it wasn't cohesive at all; it shattered into pieces too small to use. Into the trash.

The pinkish piece (top right) was a bit light, but it was pink. So I sawed off the end and found I could easily break the end-cap with my hands. Not strong enough to work. Not pretty enough for a specimen. Into the trash.

I cut one rock that looked like it might have dendrites. It was both softer than I thought and muddy enough to make my cooling oil for my saw brown. Into the trash.

I worked a bit of each of the 'tumbling' rocks on the grinder. Mud. Into the trash.

DON'T GIVE UP!

Then, I tried a rock that wasn't terribly exciting, but it wasn't mud. When I tried a corner on my grinder, it polished up a bit. It also had a nice combination of earth tones. Although it wasn't good enough for me to make as a cabochon, it works as a neutral background for wire wrapping.



I cut the next to the largest rock thinking it might be as interesting. Well, it was a conglomerate, but it had the colors and appearance of gray meat loaf that went bad last week. Into the trash.

Test Piece to check for hardness





Finally, I got to the biggest rock and yippee! It's hard, about 6 on the Mohs scale. It's still dark, but has those interesting turquoise colored bits. It polished like a dream. I was suspecting jade, and I wanted some back up opinion so I took a slice and a cab to my rock club meeting. We have a lot of experienced rockhounds and they pretty much unanimously declared it jade. I'm happy with that! Here's a picture of the side of a slice I ground where you can see the green inclusions. What do you think?
Jade rock face with finished cab. Great Shine!   



All in all, with the possible exception of the jade, I didn't find much useful, but I had a lot of fun rockhounding and checking the material I found out to see what it was. Would I do it again? Of course! I'd just try to do it  on a cooler day, so I could hunt longer.

What finds have you found at creeks and riverbeds?

Check back on August 2, for my next blog. Until then, I'm you're Lapidary Whisperer,

Donna



Wednesday, July 5, 2017

Moving Mountains in Boxes



MOVING MOUNTAINS IN BOXES – SHIPPING YOUR MINERALS AND ROCKS


          How a mineral is packaged is critical to maintaining its integrity, whether you are getting it for display or planning to commit lapidary on it. 


          When the Post Office found the package of Anthracite (yes, coal) I’d ordered, it was all by itself in a small bin. The seams and some of the fabric were gone along with about a third of my material.  The shipper had put it into one of those presumably indestructible USPS Tyvek envelope/bags.
 Guess what? The Post Office is perfectly capable of destroying them and whatever they hold. To be fair, they could have been better packed. But still . . .

When it didn’t arrive in a timely manner, I checked with the vendor who confirmed it had been shipped and gave me a tracking number. After I tracked it to the local main post office, I went over. No problem, they knew the package, because it was sitting in plain view. But no one wanted to deliver the mess, and although they claimed they sent me multiple cards advising me of where I could get it, somehow the cards had proved too difficult to deliver also. So this is what I finally received.

Chunks of coal are coming out of the bottom


        HOME FROM THE SHOW/SALE

Even when I'm in control of the rock constantly on its journey to my shop, I need  to be sure your rock’s not rolling - and bouncing other rocks in my trunk or the back of my husband's Ford Transit Connect which has an enclosed cargo bay.

Wrapping the rock individually in newspaper, towels or lots of bubble wrap is a good start for larger pieces. I then secure them in a box or other protective object and stabilized in place so they don’t go flying around when I turn a corner.  For smaller rocks/slabs, wrapping them with newspaper around them and keeping them securely together in a bag is usually enough.  I normally bring an assortment of little plastic display bags to keep soft minerals from rubbing on and being scratched by other rocks.

SHIPPING CAN BE AN EXCELLENT OPTION

When tempting stones are heavy—too heavy to carry on an airplane going home or just too large for you to manage on your own, it’s time to ship them. Some shows have on-site shippers who will handle everything from wrapping your rocks to getting them to your front porch. Warning! This is not cheap. Not even a little. However, they have the materials and shipping capability to make sure your purchases arrive intact.

  DYI SHIPPING BASICS

If you decide to take the DYI options, especially for fragile specimens, the people at Treasure Mountain Mining have created a very detailed description of how they ship minerals that have fragile crystals, etc. You can find it at: http://www.treasuremountainmining.com/index.php?route=pavblog/blog&id=36

Another DYI tip I picked up somewhere: if you really want to be sure your item isn’t smashed or damaged, especially if it is fragile, pack it securely like the directions above. Go out and purchase a new, light weight cooler like a Coleman or Igloo brand. Put the secure package in the cooler and pad it liberally so it won’t shift in transit and put the cooler back inside the box it came in. Then all you have to do is tape it closed, label and ship!
As for my damaged anthracite, I think if the Tyvek bag had been inside of a box, it would have come through fine. In case you’re wondering what I plan to do with coal, anthracite is a very hard and shiny coal. I like to do “lapidary meals” where all the foodstuffs are minerals.

Coke-a-Coala


The anthracite was crushed quite small and put in a Coca Cola glass with selenite ice cubes to be part of a hamburger meal I’m working on. When I send the anthracite donor a complementary glass of “Coke-a-Coala”, you can believe it will be packed so that not even a tiny bit of anthracite will move in shipment.
Drop me a note at Donna@LapidaryWhisperer.com and tell me about your challenges with shipping rough, slabs, finished cabs, and specimens!
Your Lapidary Whisperer
Donna Albrecht


         

Wednesday, June 21, 2017

YOU DECIDE - BEST IN BLUE, LARIMAR OR QUARTZ?


There's something about a sky-blue stone that makes me catch my breath. The color is so cool and refreshing and, especially when the color has lighter markings through it, fascinating, like it wants me to tell its story.

One mineral I've wanted to work with--a lot--is larimar. This sunny day stone with remarkable white markings always looks like it's got secrets it wants me to share. One hold-back for me has been the cost. At the shows I've been to where it is being sold, it's been about $0.65 a gram and up. If I wanted enough to make several small cabs, I was talking a lot more than lunch money. 

So, up until now, I've looked a lot, but I haven't taken any home. Notice I said "until now". 

It all started when I was at  Quartzsite last winter. I found a vendor who had some blue slabs that caught my eye. Could they be larimar? If so, the price was so low I was going to get a whole bunch of the stuff!

The vendor said I wasn't the first to ask. However, while his slabs look a lot like larimar, they're actually blue quartz from China. Here's one of the slabs I purchased from him for $17.00.





IS IT LARIMAR, OR IS IT QUARTZ?

 Then in the interests of full investigation, (It sounds better than I finally found an excuse to buy some larimar 😏), I looked online until I found larimar available in small slabs and purchased a bit. Then to test whether or not they actually looked as much alike as I'd thought they would, I made a cab of each stone. Can you tell which is which? I'll tell you at the bottom of the blog.

So, they really look a lot alike, but there are several significant differences.

1, Hardness (you thought I'd say price first, didn't you?). The quartz clocks in on the mohs scale at 4.5-5, the larimar is noticeably harder, coming in at 7 on the mohs scale.

2. Availability When I found this, it was the first and only time I've seen this particular blue quartz. I've looked online and found a lot of blue quartz listed as healing stones, but none of it had this particular color with the white included. However, it does not have the distinctive "blossom" markings often found in larimar. On the other hand, larimar is pretty widely available, if costly. I purchased mine from ncestones on eBay, but there are many other vendors out there selling all qualities of this mineral.

3. Price Okay, this was a math problem. Everything had to be converted to one scale in order to compare prices realistically. I decided to go with grams, since that's something we frequently see as a weight measurement at shows.

At shows, the price for larimar I've seen most often is $0.65/gram.

The larimar I purchase on line was sold by the carat weighing out at 274.5/ct. I converted it to grams and the price was $0.44/gram.

My slab weighed out at 3592 grams. I paid $17 for it, coming out with a price per gram of $0.005. Yes, that's right, roughly one one-hundredth of the price of the larimar.

As you can see, there can be an enormous difference among the prices you can pay to make a pretty blue cab. There is a significant price cut to purchase online, but you have to count on the pictures to know what you have (if possible, see both sides because if the "b" side is important to you, you want to be sure it looks great).  But, the shortcoming of purchasing online is that you can't see it and touch it before you purchase.

While the blue quartz does make some lovely cabs, the larimar wins my vote for rock to cab. Since it is much harder than the quartz, it takes a much, much better shine!

ANSWER

The larger stone on the left is the quartz, the smaller stone on the right is the larimar. Did you guess right?

I'd love to hear from you. Let me know about the rocks you're working on Just click on the "Comments" section below!

See  you next time, Your Lapidary Whisperer,

Donna Albrecht


Wednesday, June 7, 2017

CABS I FOUND HIDING INSIDE THUNDEREGGS



My favorite Thunderegg cabochon
I used to think that thundereggs were, to be honest, boring. The first ones I found had milky-colored stones that were often too small, misshapen, or simply not interested in telling me a story.

Then, I started getting lucky once in a while. The first lucky thundereggs were table agate stripes of quartz layers in different shades like this one. Now, in and of themselves, these stripes aren't all that fascinating, but the thunderegg assured me that I'd find a story if I just kept looking.

The one thing I was sure of was that I did not want to include any of the non-quartz material in my cab, so I sliced this and decided to go with a free-form shape and see what happened.




GUESS WHAT I FOUND!

I found a little race car! In the picture you can see the rear wheel and the head of the driver in the cockpit. The circles are cross views of tube agates that also grew with the table agate inside the thunderegg, but were not visible until I had ground the agate into the curved cab shape. I had designed the free-form shape of this cab before I started grinding, so I didn't know about the car yet, but I love the way the shape makes the car look like it's moving.



MAKING THE MOSS OF IT

This slab from a double thunderegg had a lot of moss running through it. It turned out to be mixed blessing. On one hand, the moss itself is lovely, however, on the other hand, the quartz is a smokey gray color.

I was ambivalent about working it until I saw it back-lit. It was amazing! The smokey color faded out to yellow and the fanciful moss became distinct with crisp edges and gave the impression of floating.

It's a nice cab for my collection, but I doubt I'll ever mount it for jewelry because it's much less impressive without the back light.




BREAKING MY OWN RULES

Earlier, I mentioned that I I don't like to include the non-quartzy material when I make cabs from thundereggs.

Except for this one.

In working with the exterior material, I've had problems because it tends to be somewhat soft, happy to have small chunks fall off, and refuse to take a polish or even a bit of a luster. For this free-form, I would have lost the full shaping of the material, and I was afraid I'd also lose the golden color. When I made this shape, I could feel the gold colored material and it was slightly rougher than the agate center, so I didn't want to get in close and risk losing the red and gold embellishments.




For those of you noticing the cab is on its side, well, no matter what angle I took the photo from, and no matter how many times I edited it before bringing it into the blog, it kept insisting on returning to this view. Since my rocks tend to talk to me, I finally decided it was saying it liked this view best. So it is what it is.

I also love the way the interior circle-ish shapes give the impression that it is a blue whirlpool and it is breaking off parts of the gold edge and swirling them away.
                                                                                                                                                                                 


Have you ever found a really incredible cab inside a thunderegg? If so, send me a picture and maybe I can use it in another blog post.Click here to reach me!

Your Lapidary Whisperer

Donna Albrecht

Wednesday, May 24, 2017

LESSONS I LEARNED CABBING PREHNITE





*Don't Miss My Big Announcement at the End of this Blog!*

It was a bright, sunny day in Quartzsite, AZ when I saw a tarp on the ground with creamy light green stones, and I was smitten. It came all the way to Arizona from South Africa, just for me. The vendor only had rough and a few cabs (I don't remember seeing any slices), so I didn't see below the exterior bumps like the ones in this picture of the outside. 
Prehnite rough





 PROBLEMS AS A CABBING MATERIAL

Backlighting shows the structure inside the stone
First, the prehnite felt fairly soft to me when I was working it. According to Mindat.org, it's 6-6.5 on the mohs scale. When I was working on it, that felt like it was softer, but it took steel to scratch it, so I guess Mindat's  right. It is usually seen in translucent colors ranging from clear to green or yellow, or gray. One deposit of orange prehnite was discovered in South Africa.

The structural material visible in the back lit picture of a cab, was somewhat harder than the areas without it.  Also the black tourmaline inclusions have a mohs rating of 7, providing even more variation in the hardness when I'm shaping and polishing the stone.It doesn't seem like much of a difference when you look at the numbers, but it was really noticeable when I was working it. So as I tried to polish my first cab, I kept using very fine grits on it and the soft material ground out faster than the structural stone and tourmaline, giving me a bunch of low points, which, of course, wouldn't make a smooth surface.

YOUR LAPIDARY WHISPERER LEARNS

The next time I worked with this, I decided to go with a free-form shape and the prehnite cooperated a bit more (or maybe I was listening better). I also skipped my first wheel and went right to the 220 to start. I worked quickly and with a light touch. This time, I had a much better result as you can see in the picture at the top of this blog. Because of the nature of this material, I didn't really get a polish, but I finally did achieve a nice luster by not overworking the cab.

I'm glad I didn't get a lot of this material. I have one more smallish slab left, but I think it's going to spend some time in the box until it feels chatty.

Drop me a note and show me what you're up to in your lapidary shop!


ANNOUNCEMENT * DON'T MISS MY ARTICLE, "HARD ROCK MEALS" in the June edition of ROCK & GEM MAGAZINE! In it, I show how I created a case for shows that has a whole "meal" that's made completely out of rocks!!!











Come back on June 7, when I'm getting back inside rocks again. This time, it's not geodes, it's Thundereggs. Normally, they're not a favorite of mine, but wait until you see the cabs I've been able to make with what I've found inside!



See you next time,

Donna Albrecht
Lapidary Whisperer

Tuesday, May 9, 2017

FIVE WAYS TO SEE HORN CORAL
  
The resemblance between this coral and the horn of a cow is obvious, especially if the narrow end had extended on, getting smaller as it went. But the large end was the open growth area and the smaller end attached itself t the sea floor.

Scientifically it's known as rugose coral (Grewingkia canadensis)  Sadly for coral with such a beautiful color and fascinating growth pattern, it is extinct today.  It's heyday was during the Ordovician period 488 million years ago to Permian Period that ended 251 million years ago.

The coral animals formed these horns often in an individual structure, although they sometimes clustered structures as colonies.The animal lived at the large end of the calcium carbonate cone and grew on top of dead coral animals.Look for them in the midwest states if you're rockhounding.








FUN STUFF

The outside of horn coral is interesting, but the real fun is inside!  Traditionally, lapidarians slice it across the grain and polish it for display. The grey-brown material around the beautiful coral, is very soft. If you want to make a cab, plan to mount it in a bail that entirely encompasses the edge. I started it on my second wheel 220 grit and worked it gently. I found I could still make subtle changes up to 14,000 grit--it's that soft. Then I finished it off with a 50,000 grit to give it the best polish I could.
This cab wasn't nearly centered in the material, but it came out looking really nice. The white line is from the lights I used to help the colors show up.





This second piece is more of a rough medallion than a cab, At this cut, there was a spray of coral that went all the way to the edge. I've never seen that before, so I thought I'd preserve it. This is the next slice after the one above.


CURIOSITY CUT THE CAB

When I'd worked with the other pieces I'd noticed that the markings out from the center of the slices reminded me a bit of dendrites so being curious by nature, I cut down a side to see if it had the speckled dendrite look that you get when you change the cut by 90 degrees. And it does!  Try expanding the image on your screen and you'll see it.



 Thanks for visiting me here at Lapidary Whisperer. Next time I expect to be showing some Floy Wash Jasper--if it decides to cooperate. So far, not what I'd hoped it would become.

Visit www.LapidaryWhisperer.com on May 24 and see if it worked out. Please share this blog with your lapidary-inclined friends, or friends who just like rocks.

See you next time,

Donna Albrecht
Your Lapidary Whisperer

Wednesday, April 26, 2017

GEODES! CRYSTAL FANTASIES HIDING INSIDE ROCKS

Dugway Geode





Geodes capture the fancy of lapidarians, rock collectors, rock hounds and everyone else who loves a pretty rock.

We've all seen beautiful geodes in shows and shops, and often made them ours.  The Dugway geode pictured here is a perennial favorite with its halo of colored quartz stripes that polish beautifully to make the display piece even prettier. 





WHAT MAKES A GEODE A GEODE?

Moroccan "Potato" or "Sugar" geode
Not every stone with a natural hole in it is a geode.  Mindat.org defines a geode as a "chalcedony (cryptocrystalline quartz) shell lined internally with various minerals, often as crystals." Sometimes the shell is very easily viewed as in the Dugway above, other times the matrix it was formed in has all worn away and you get the spectacular Moroccan geode shown here and often called Potato Geode for the way it looks on the outside, or Sugar Geode for the way the quartz crystals look inside.

Geodes usually start as a gas pocket in igneous or sedimentary  minerals or a nodule that washes away leaving a roughly spherical space. Over time, waters and gasses passing through leave deposits of crystals that are colored by various minerals.

And while they're all unique, for the most part, each one is similar to the next. But every once in a while . . .

I like to look for the geodes that whisper stories to me like the one below. There's always something about story geodes. Often it's an inclusion whether it's simple or complex.

I left the picture large to make it easier to see the inside which at its longest inside measurement is barely one inch tall.

When I first saw it, I thought the metal-looking wedges inside were iron because of the rusty look that was descending from the opening and at the spot on the top.  But (a) it's not shaped like most iron and (b) it's not magnetic. The second object looks as if it has flakes like mica, but mica comes in sheets as you may be able to see, the front object has a long triangular shape. I can't see enough of the larger one to tell if it is triangular, but there is one on the top that doesn't show in the photo which also has the triangular or wedge shape. What do you think it is?  If you like sci-fi, the whole geode looks a bit like a mine on an ice planet to me.

I wish I had a picture of the most ominous geode I ever saw. It was a very large amethyst geode, about four or five feet tall. The thing that set it apart was a single long white crystal pointing into what had been the center. Once the seller had displayed the geode on a stand, the white crystal looked like it was aimed at the viewer's heart. It was scary and I wouldn't want it in my house!



Now, this definitely is a fun geode slice. The long structure you can see in the middle of the geode is hollow which I can tell because the back is sliced through the geode structure too.

The image below shows the back side of the geode slice with three hollow areas circled. Two are structures shown in the geode and the third can barely be seen in a separate geode structure above.
  
PLEASE NEVER "CRACK" YOUR GEODE!

A geode is a natural work of art, not a rock to play "Whack-a-Mole" on! When I see someone at a show who offers to sell geodes and then hit them with a hammer, I want to take the hammer to some sensitive orb on their body. Yes, a hammer will get you into the rock, but it will be shattered into sharp-edged pieces that forfeit the story and the glory they were meant to have.

Always, always open a geode with a saw. You can probably us a hacksaw on the more fragile Moroccan geodes, or a workshop or tile saw on a geode in a vise, but the gold standard is a lapidary saw that's roughly proportional to the geode you're opening. For example, a 10" lapidary cutting saw can easily handle a geode that's up to about 4" tall. I prefer to do the cutting by hand so I can rotate the geode as I go, preserving any crystals or druzy that go more than half way through the open area.

Not every hole in a rock is a geode, vugs are both very similar and very different from geodes, and of course, there are thundereggs which aren't exactly a hole in a rock, but have similarities. But those are for another time.  Come back on May 10 for a new blog by your Lapidary Whisperer. You can be sure you get it directly into your email by subscribing at the icon on the upper right corner of the blog.

Yours for Lapidary Fun,

Donna Albrecht
Lapidary Whisperer