Stone of the Week - Unknown Lovlies

Hello again! I know it’s been forever since my last post here – not that this is an excuse, but we had the October show & then the business building up to and then after it I have completely neglected my writing here. I have missed it much.

I was out for a walk the other day & noticed that Fall has snuck up on us quite quietly out here. With all the explosive colors and cool evenings we are in full Fall force. Every so often while on my walks I find curious stones and bring them back to our office. I honestly do not know what half of them are in the world of gemstones, but I just like them. Generally I keep these stones for myself, but this one I wanted to share with you all. I just thought it was wonderful in all its natural beauty. Let me know what you think.

Can You Dig? India Green Sand

India Green Sand Rough

Indian Green Sand Country of Origin - India

The Indian Green Sand stone is a form of aventurine. It is rich in chrome-like mica, which is no wonder that it’s found near a mica mine. Aventurine is a form of quartz, characterized by its translucency and the presence of mineral inclusions that give a shimmering or glistening effect. The most common color of aventurine is green, but it may also be orange, brown, yellow, blue, or gray. The mostly dark green with metallic glittery appearance is caused by inclusions of mica. Red to gold-brown is caused by the inclusion of hematite leaves. Because aventurine is a rock, its physical properties vary. Aventurine which is often banded and has an overabundance of fuchsite may render it opaque, in which case it may be mistaken for malachite at first glance.

India Green Sand Cabochons

Deposits are found in Brazil, India, Austria, Russia and Tanzania. The majority of green and blue-green aventurine originates in India, Creamy white, gray and orange material is found in Chile, Spain and Russia. Strawberry Aventurine is reddish brown and mined in Brazil. Main markets for aventurine are landscape stone, building stone, aquaria, monuments, and jewelry. India is the leading producer of muscovite mica or potassium mica in the world. As a country, India is rich in natural resources. It produces and works with roughly 100 minerals, which are an important source for earning foreign exchange as well as satisfying domestic needs. While mining those natural mineral resources, miners often find beautiful and valuable gemstones such as this.

Can You Dig? Flowering Tube Onyx

Earlier this week, someone asked me "What is Tube Onyx?" - and honestly I had no idea. So, I did a little research & here's what I found:

Tube Onyx
Country of Origin – U.S.A. (Utah)

Onyx was a common term in the TAG area and the Ozarks during the 19th and early 20th century. It was used for certain kinds of calcite or flowstone which are banded, similar to true onyx. The true onyx is also banded, and looks very similar, so the main difference is; onyx is composed of quartz, cave onyx is composed of calcite, so needless to say cave onyx is a softer stone.

The calcite concentrations in caves are banded as they are deposited very slowly, layer by layer. These are referred to as speleothems. The color depends on the climate outside, which changes continually, and the amount of pigments like iron oxide brought in by the water. So they have typically brown, beige, white and transparent banding. Much rarer are other colors like blue and green, which are typically based on copper oxides.

Flowstones are composed of sheet like deposits of calcite formed where water flows down the walls or along the floors of a cave. They are typically found in "solution” or limestone caves. However, they may form in any type of cave where mineral rich water enters.

Flowering Tube Onyx Unpolished - photo from Yuku

Flowing films of water that move along floors or down positive-sloping cave walls build up layers of calcium carbonate (calcite), aragonite, gypsum, or other cave minerals. These minerals are dissolved in the water and are deposited when the water loses its dissolved carbon dioxide through the mechanism of agitation, meaning it can no longer hold the minerals in solution. The flowstone forms when thin layers of these deposits build on each other, sometimes becoming rounder as the deposit gets thicker. There are two common forms of Flowstones, Tufa and Travertine. Tufa is usually formed via the precipitation of calcium carbonate and is spongy or porous in nature. Travertine is a calcium carbonate deposit often formed in creeks or rivers its nature is laminated and oftentimes includes such structures as stalagmites and stalactites.

The deposits may grade into thin sheets called "draperies" or "curtains" where they go over overhanging portions of the wall. Some draperies are translucent, and some have brown and beige layers that look much like “cave bacon”.

Polished Tube Onyx Cab - photo from Flicker

As in interesting note: Though flowstones are among the largest of speleothems, they can still be damaged by a single touch. The oil from human fingers causes the water to avoid the area, which then dries out. Flowstones are also good identifiers of periods of past droughts, since they need some form of water to precipitate, the lack of that water for long periods of time can leave traces in the rock record via flowstones. (most of this information came from Wikkipedia.com)

Can you Dig? Geodes

After creating a weekly deal with our geode pendants & getting the chance to look at all these fantastic stone pendants, I wanted to take a moment to emphasize how truly unique this find is. Our geodes came from Mexico where we have worked closely with the miner for years on many projects. These small orbs are handpicked, sized and sorted. Each formed in an ocean floor volcano, which is now in Chihuahua, Mexico. Rarely are there ever two alike & why would you want them to be? With either or both crystal formations or addition of agate bands, the color range from white, to pinks, to red or light blue – maybe even black. I’m truly smitten. Can you tell?

In Tucson during the gem & mineral show companies haul in giant cathedral geodes - here are a few that are still in crates - these happen to be amethyst.

Smaller geodes can be "barreled" - the shelf in the background holds cut and polished agate geodes that can be used as home decor.

Here are a few more of the larger geodes - at this show there was a geode the size of a small truck, really, that was placed at the doors. We took pictures but apparently didn't archive them well. Ooops!

While I was looking up info on these pendants I ran across some info regarding how they are formed which is pretty interesting stuff. There are two theory’s on how these orbs are formed. One is formed in Lava & the other is formed in Dolomite. Since there is no easy way to explain how they are formed, here is a thorough explanation I picked up from ehow.com that I found to be quite interesting:


While experts don't know for certain how geodes are actually formed, there are theories among geologists about the processes that take place. There are generally two types of geodes. One geode is made out of lava. The other is made from dolomite, a limestone-like sedimentary rock. Each geode is created through different processes. All geodes, no matter how they are formed, must contain hollow bodies in which crystals can form.

Some geodes are formed out of molten lava rocks. After the molten rocks cool, they create gasses that, when dissolved, turn into bubbles. These bubbles turn into cavities once the rocks harden. The early stages of these cavities are called thunder eggs. According to experts, the minerals that form into crystals may have flowed into these cavities in two ways. Either the minerals could have come from the hot water flowing through the cracks in the lava rocks as they cooled, or they could have been deposited much later as mineral groundwater. However the convention minerals such as quartz are introduced into the thunder egg through a flow of water, thus creating the opportunity for crystals to form.

The formation of geodes from dolomite is much more complicated that those formed out of lava rocks. The theory of how dolomite geodes are formed came from geologist Robert Maliva in 1987. His theory goes that the geode cavity formed from a small, hard spheroid that later dissolved and became a cavity, a process that began over 350 million years ago in the warm, shallow waters that once covered what is now the central United States region. Lime sediments grew in the warm saltwater. When the saltwater interacted with sediments rich in calcite, the calcite metastasized into the minerals dolomite and anhydrite.

The anhydrite then turned into hard spheroid bodies inside the dolomite. Meanwhile, the dolomite changed from sediment into a hard rock. Anhydrite will dissolve even in the slightest amounts of acid in water. Thus, after acidic water was introduced, outer areas of the anhydrite broke away and were replaced with quartz, which were in the beginning only small fibers of crystal. The centers of the anhydrite bodies were then dispersed completely. Quartz was fed through the rock from water rich with minerals, forming the crystals that grow inside. Over time, the rocks disintegrated, leaving the dolomite to open the elements and causing it to dissolve. The hardened quartz then separated from the dolomite, turning into geodes formed on the ground.

Stone of the Week – Turquoise of Course!

I was just checking out the September 2010 issue of Cowboys & Indians and much to my surprise I came upon a wonderful U.S. turquoise feature story. The author of the article, Dean Krakel, discusses three or so turquoise mines which are here in New Mexico & in Arizona. He not only covers the history of the mines, but as well features three miners who still look after their claims in these areas. Wonderful ~

Here is a quick paragraph from the article:


“There is no other stone like turquoise,“ he says (referring to Doug Magnus owner of the Alicia Lode, Castilian and the Tiffany mine). “The color and beauty of it are unique. It’s mysterious and spiritual. The ground here is alive because of it.” Discharged from the Army in 1968, Magnus came to Santa Fe in search of something he couldn’t name. Inspired by Native American artistry and the concho belts worn by Jimi Hendrix and Jim Morrison, Magnus began making his own silver jewelry because he was too poor to buy it.

Try to pick up this issue & you will fall in love with turquoise again, and again, and again.

Turquoise...read about this amazing stone.

So many of you are posting that your favorite stone is turquoise, we can't blame you at all!! Its definitely a top ten for us as well. Here is a great link to Wikipedia that tells everything you ever wanted to know about this fantastic stone. Enjoy!

http://en.wikipedia.org/wiki/Turquoise