Thursday, December 5, 2019

Cotton Candy Agate for the Holidays?

BECOME A ROCK SHOW VENDOR?  See my article in the December issue of Rock & Gem Magazine! 

When I first saw a slab of peach and white cabbing material, I thought it looked like a sweet confection; then I saw its name, "Cotton Candy". It fit.

Then I showed it to an older rockhound, who authoritatively told me it was "Youngite". Being a curious sort, I decided to find out if they were one and the same thing. Frankly, I thought it was likely they were, but appearances can be deceiving.

YOUNGITE

Youngite (SiO2 ) For many years, this was a popular slabbing material that was not terribly hard to find even though it was only mined in one place inside the Youngite caves near the Glendo and Guernsey reservoirs in Guernsey, Wyoming. The  online expert on this stone is Mike Nelson, I got my information from him personally and his blog site, check it out: Click Here

Mike says  Youngite is a brecciated reddish-brown to peach jasper that was then re-healed by deposition of cream-colored chalcedony.  Often the entire rock is then covered by druzy quartz crystals.  At one time Youngite was fairly common on the market as collectors were able to pull numerous specimens “off the walls” in Youngite cave(s) and voids near Guernsey.  He says he understands that the caves are in the Guernsey Limestone and the breccia clasts are actually derived from the limestone.  


Image Credit: Midat.org





This image shows the common exterior with botryoidal  drusy quartz coating. The quartz portion is fluorescent, which is the quickest way to discover whether you have true Youngite. The Cotton Candy stone is not fluorescent, even though it often looks the same.



Credit: Mike Nelson






Unfortunately, the area where the Youngite was mined is  reported to be mined out and the specific area is no longer open to the public. There are some pieces available, generally at a pretty high price point. If you're considering investing in some, I suggest you ask the seller for regular and short-wave pictures from the same angle to be sure you're getting the real deal.

COTTON CANDY

When I described my Cotton Candy slab and told him I believed it came from Mexico, that explained a lot of the differences between the two similar rocks.  Most of the agate in that part of Mexico comes from volcanic rocks like Retaliate nodules rather than sedimentary limestone like Youngite. The brecciated materials in both probably get their color from iron in them.

So, they really are very different rocks. 


IN MY SHOP



I purchased this slab as "Cotton Candy" at a local rock show.  As you can see, it's pretty dirty and my impression was that it was quite weathered, which turned out to be true. The colors changed dramatically when I worked with it.
My finished cab from the slab above,

You can see the pencil marks I made around the void that has the druzy coated botryoidal shapes and that I used to set the shape.

After I got it cut, shaped, and polished, you can see the yellow-looking matrix has become white with a touch of blue tinge.  The peachy material has finished out as pink and there are obvious bands around the void and the pink. It took a lot of scrubbing to clean the interior shapes, but it was worth it.




My Youngite cab






I had purchased a small slab of Youngite years ago without knowing what it was, and made a cabochon with it. How do I know it's Youngite and not Cotton Candy?  It's fluorescent! 

Youngite contains chalcedony and quartz, so it fluoresces mostly green. I tried my teardrop cab above under the long and short wave lights, but nada. That was a real surprise since the botryoidal formations inside the vug appear to be quartz druzy, but they obviously aren't.

To see how Youngite lights up, check out the image on Mindat.org at Click Here.


Also, when you look at the two cabs, you'll notice how very similar they are. But, a very close examination of their mineral components shows that they are not the same thing at all. Sort of like green gemmy faceted stones. Are they apatite Ca5(PO4)3(Cl/F/OH) or are they emeralds
Be3Al2(Si6O18)? The only way to know for sure is to consult a gemologist.

From a lapidary standpoint, I feel that both materials are excellent lapidary material. They are nice to work with and take a beautiful polish. I would caution about what I noted earlier. Because of its current rarity, real Youngite commands a relatively high price in the market.  Cotton Candy is commonly available. If you are considering a purchase, be careful you get what you pay for.

Until next time, I hope  you find joy (and great rocks) through the holidays you celebrate this time of year.

Your Lapidary Whisperer,

Donna







Saturday, October 5, 2019

CRAZY FOR CRAZY LACE AGATE

I loved working with the peach and white stone


Crazy Lace agate is a lapidary dream rock. It's basically a banded calcite, but it's so much more! The bands can come in almost any color, they can swirl, encase spheres, bend in fortifications, and even feature druzy coated vugs.  This stone is mined in the Mexican state of Chihuahua. Some claims in the area name the area name of stone after itself like the Noriega. And yet . . . Rodeo Flats agate from Arizona looks pretty much the same as does some agate mined in Morocco. 



This slab isn't high quality, but I love the pattern








Did I say any color earlier? Well, when it comes in all blue, sold as blue crazy lace, it's definitely not from Mexico. Blue lace agate primarily comes from Namibia and South Africa with a bit in Romania. You'll often see them sold side by side with other lacy-patterned agates, but they are far distant cousins.
 


   
This Crazy Lace has color and motion


In case you're wondering, I included this picture because I could!  This one is so chatty that it won't slow down and tell me what it wants to have done with it. So, for now it's safe . . .

although . . .

if you look at it from either side, you can see landscape scenes with a bit of blue sky.












The slab has the beautiful sunsets I hope to use 


THE LAPIDARY EXPERIENCE

 As the Lapidary Whisperer, I adore this stone!  The colors and patterns tell me so many stories, and the stories can change simply by moving the templates around. It is also fun to create shapes by using a pencil to create the shape that shares the story the slab is trying to tell you. I've found that on occasion, I can incorporate the outer edge as a feature in the cab.

This slab is driving me a bit crazy. It wants me to use the sunset orbs, but the problem is they are very shallow and don't even show on the back of the slab, I'm afraid if I do any grinding, they'll disappear completely.

The good news/bad news is that this is not a fast mineral to work. It runs right about 7 on the Mohs scale and tends to take a while to work, especially on the lower number grit wheels. The good news is that it will take a nearly gem-like finish.

Be aware that if the colors of your crazy lace are unusually intense, it may be dyed and the colors will fade over time, especially if exposed to the sun.  If the intense coloring is limited, like the slab below, it is probably natural. 

A busy natural slab with red staining

HISTORY?


I found only a few references to the history of this stone and the conflicted like . . . crazy! One source claimed it was first discovered in the late 19th century, and then forgotten until a construction crew found it when they were clearing land for road construction in the mid twentieth century.

Cerridwen, image: Bing

Yet, it had apparently already been discovered in Mexico long before the Spanish Conquests by pre-hispanic people who used it to appease the gods or as an amulet for those fighting wars. I even saw a site that credited this stone to Cerridwen in Celtic mythology (Gods of Ireland, Scotland, Wales and Gaul)  heaven knows how they got rocks from Mexico.



While I'm not into assigning mystical property to minerals, I saw several places where it was referred to as the "happy stone". Okay, I'll partially buy into that. Working with crazy lace in my shop does make me happy, because it makes such incredible cabochons.





NOTE: Except for the image from Bing, all the other images are mine. If you want to use them, please ask.

Until next time, I'm your LAPIDARY WHISPERER

Donna