Wednesday, April 11, 2018

BIG CATS AND OTHER ZOO-THEMED JASPERS


Leopard Jasper Slab:ption


Some time ago, I wrote a post about zoo-themed jaspers. Since then, I've been able to acquire two big-cat themed slabs I really love.  So I decided to update this classic blog post with the new materials. Another reason I went back and updated this post was that I realized I had a number of cabbing materials that weren't just named for animals--they were petrified remains of animals! I'm working on a future blog post about those materials . . . and I bet you'll be as surprised as I was about how plentiful and varied they are!

BIG CATS

The Leopard Jasper at the top of the blog has a lot of amazing stories it wants to tell this Lapidary Whisperer.  I see a red brick wall separating the wilderness above and the homes, fields, and streams below.

The Cheetah Jasper, on the other hand, tells stories of camouflage in the wild and stories hidden behind the dots.
Cheetah Jasper

ZEBRA JASPER

When I first posted this blog, , 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 amazing 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, March 28, 2018

FASCINATING FLUORITE





My favorite thing about Fluorite is the way it mimics other stones. For example, if I had cut a long, thin strip of the slab above and then cabbed it, it could appear to be Tourmaline. It can even look at bit like Amethyst if you get the pictures just right.

Fluorite 

 KNOWING IS HALF THE BATTLE

There's a HUGE difference between Fluorite and Amethyst or Tourmaline as any lapidarian can easily tell.  Fluorite is only a 4 on the Mohs harness scale. Amethyst is a much harder 7 and Tourmaline is a 7-7.5. So working it for lapidary purposes has two problems. First, it doesn't take much of a polish (full disclosure: the Fluorite pictures for this blog post were taken when the rocks were wet). Second, because it is so soft, unless you coat it with a shellac or something similar, it will scratch easily.

A cool piece of somewhat fractured green fluorite

NOT NAMED FOR ITS LOOKS!

This mineral was officially named by Carlo Antonio Galeani in 1797. His inspiration was the fact that it was used as a flux in iron smelting to reduce the viscosity of slags. He gave it the name from Latin "fluere", to flow. Over time, fluorite has also been used as a flux in the manufacture of some glasses and enamels.

BUT LOOK AT IT NOW!

According to Nightsea.com  Sir George Stokes (1819-1903), a mathematics professor at the University of Cambridge, gave the effect its name. In the early 1850’s Stokes noted the color shifting effects in the mineral fluorspar and investigated in greater detail. A key experiment was using a prism to isolate ultraviolet light and observe blue emission. He was first inclined to call this ‘dispersive reflection’, implying a reflection to a different wavelength. He wrote:“I confess that I do not like this term. I am almost inclined to coin a word, and call the appearance fluorescence, from fluor-spar, as the analogous term opalescence is derived from the name of a mineral.” I agree with Stokes, dispersive reflection doesn't sound half as nice as fluorescence.

Natural light

Same cab, back-lit with UV light



I'm finding his whole fluorescent thing pretty interesting and I'm planning to do a blog post on it soon!

GIVE ME THAT FLUORITE GRIN!

Yes, the fact that the mineral "Fluorite" and the toothpaste additive "Fluoride" sound alike is no accident; but don't try rubbing your mineral samples on your teeth.

The Food & Drug Administration has approved three compounds, stannous fluoride, sodium fluoride and sodium monofluorophosphate as toothpaste additives to prevent cavities. The compounds are manufactured by reacting sulfuric acid with fluorspar, a calcium fluoride ore.

It apparently doesn't take much. The box for my Crest Complete lists sodium flouride (NaF) as the only active ingredient and it is only 0.243% of the product.

Hope you enjoyed this blog post. If you'd like to comment, go through the instructions at the bottom or email me directly at Donna-at-LapidaryWhisperer.com

Until next time, I'm your

Lapidary Whisperer

Donna Albrecht