However, along the way, I got diverted by some very interesting facets of amethysts, including some pretty neato human history. So in today's post, we're actually not going to talk much about geodes at all. Believe me when I say we'll get there soon, though!
So, everyone knows amethyst is a purple variety of quartz, yeah? And we're used to it being abundant and fairly inexpensive, aside from those jaw-dropping giant geodes and some really fabulous art. So, it may shock you just a little bit to learn that gem-quality amethyst used to be considered just as valuable as rubies, celebrated in myth and legend.
Rhea the Titan gave it to Dionysus, god of wine, to preserve his sanity from the vine. Royals and nobles sported it proudly. It even ended up in many a country's crown jewels. It remained an expensive stone, reserved only for the fortunate, right up until ginormous deposits were found in South America in the s.
Once those mines started producing, amethyst became available in copious quantities, and now you can buy some really nice specimens for the price of a gourmet coffee or few. Good news for those who want a bit of their birthstone for their own selves, isn't it? Even without those sources, amethyst is fairly easy to track down, even if gem-quality specimens are less abundant. It's found most places where quartz ends up: in both extrusive and intrusive igneous rocks, in metamorphosed rocks especially in alpine-type fissures , hydrothermal veins, rocks deposited by hot springs, and even some sedimentary rocks.
Same radiation that creates your basic Incredible Hulks. Instead of the big green guy, they could've gone with purple and it would've been science. See, you can have clear quartz that has iron substituting for some of the silica in its crystal lattice. Though the color is stable with normal use, this is not a birthstone to wear to the beach every day. Amethyst birthstone jewelry can be cleaned with an ultrasonic cleaner, but steam cleaning is not recommended.
A soft brush with mild soap is the safest option. Having the same chemical and physical properties as its natural counterpart, synthetic amethyst has been known since the s. In some cases, it is very difficult to distinguish natural from synthetic amethyst without access to advanced gemological testing. The GIA Laboratory can tell the difference, but many in the jewelry industry do not request testing because of the cost and time required to determine the origin of what is a comparatively inexpensive gem.
Still, merchants are required to tell you if a gem is natural or synthetic. Amethyst has enchanted kings and queens for many centuries. Now you know how to buy a royal gift for your love with a February birthday. And for some quick tips, take along our Amethyst Buyers Guide the next time you go shopping. Amethyst Birthstone. Courtesy: N. That is when trace amounts of iron are incorporated into a growing quartz crystal. After crystallization, gamma rays, emitted by radioactive materials within the host rock, irradiate the iron to produce the purple color.
The intensity of amethyst's purple color can vary from one part of the crystal to another. Amethyst crystals grow slowly and the composition of the fluids delivering the iron and the silica needed for crystal growth can vary. The darkest color of amethyst forms when the largest amount of iron is incorporated into the growing crystal. That is what causes color zoning. Color zoning influences the marketability and value of amethyst. Most people want a gem with a rich and uniform color.
As a result, gems of uniform color - no color zoning - are the most desirable and the most valuable. Color Zoning in Amethyst: Amethyst crystals grow slowly, and the composition of the waters from which they grow can change over time. As the composition of the water changes, varying amounts of iron are incorporated into the surface of the crystal. Later, radiation emitted by minerals in the surrounding rock modify the iron to produce the purple color.
This can cause the crystal to have zones of different color intensity. Each of these zones records a time interval in the growth of the crystal similar to the growth rings of a tree. The gem in the photo above shows dramatic color zoning. Although this is geologically interesting, the most preferred amethyst gems have a rich, uniform color. The physical properties of amethyst are almost identical to the physical properties of other color varieties of quartz. The only important difference is the color of the material.
Purple Chalcedony: Chalcedony can occur in a wide range of purple colors. It is often improperly called "amethyst" or "amethyst chalcedony. They are improper because purple quartz amethyst and chalcedony are two different gemological materials. The name chalcedony is used for microcrystalline quartz -- quartz that is in crystals so small that they cannot be seen without the aid of a microscope. Fortunately, it is easy to tell the difference between quartz and chalcedony.
Quartz has a vitreous luster on conchoidal fracture faces, while chalcedony has a dull luster on conchoidal fracture faces. If you use a hand lens or a microscope to examine the facet junctions on a faceted stone or the boundary between the flat base of a cabochon and its domed sides, you can usually find at least one tiny conchoidal fracture.
There is where you can observe the luster. These materials also have a difference in refractive index. Purple chalcedony and lilac chalcedony, are acceptable names for this material.
The name "amethyst" is an incorrect varietal name when used as an adjective for chalcedony. Small amounts of amethyst are found at many locations throughout the world in igneous , metamorphic , and sedimentary rocks. Faceting, cabbing and ornamental grade amethyst can be found in all of these locations; however, the amount is usually insufficient to support an ongoing mining operation.
In Brazil and Uruguay large amounts of amethyst are found in the cavities of basalt flows. Large cavities can contain hundreds of pounds to several tons of amethyst crystals. Smaller cavities, known as geodes , are often opened in a way that displays the crystals inside and then fitted with a base that allows them to be used as home or office decor.
They are popular sales items at rock shops and mineral shows. Four Peaks is the most important amethyst mine in the United States and is famous for producing amethyst with a reddish-purple color.
This is a It was cut by Jack Lowell of ColoradoGem. Amethyst has been produced at many locations in the United States.
Much of it has been as a byproduct of other mining operations. The mine is well known for producing amethyst with a reddish purple color. The deposit was also known by Native Americans because a few amethyst arrowheads have been found nearby. Some of the amethyst in the Spanish crown jewels may be from this deposit, brought back to Spain by Spanish explorers.
Amethyst is best known as a purple, transparent, faceted gem that is sold by the carat. These include amethyst geodes , amethyst crystal plates, amethyst crystals and amethyst tumbled stones. The amethyst geode market is very strong, with many tons of them being sold at the Tucson Gem and Mineral Show alone. Yet in the very instant the tigers leaped. Artemis protected the young maiden by turning her into a statue of pure white quartz. In remorse for his actions while in a state of drunken anger.
Dionysus then poured his cup of grape wine over the pure white quartz statue. Giving the quartz statue its beautiful violet-purple color as well as bestowing Amethyst with a power to prevent the effects of alcohol. Found throughout the Old World, almost every culture placed great value in Amethyst. With the dark purple stone quite possibly being the worlds first precious gem.
Although people do not generally think of the royal stone as a prominent gem in ancient Egypt. With the blue colors of lapis and turquoise prevalent in Egyptian artifacts. There are examples of the royal stone in Egypt dating as far back to BC. Ancient Egyptians wearing amethyst to protect against guilty and fearful feelings, as well as a protection against witchcraft. While the Bible describes amethyst in Aarons Breastplate in the book of Exodus 19; as the third stone of the third row in Aarons Breastplate.
With the gem representing the Israeli Tribe of Dan. The Hebrew gave Amethyst the name Ahlamah or dream stone. With the belief in Hebrew culture that the crystal provided pleasant dreams.
Also used In ancient China, amethyst became a powerful tool in the art of Feng Shui. Used by masters of the art.
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