Author:
Knut Holt
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Date Posted: 01:24:31 01/21/14 Tue
Gemstones in the Quartz Group - Noble but Affordable
Quartz gemstones have their own unique beauty, and they are as noble as much more expensive stones. Learn more about them here.
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Quartz and related minerals are very common in rocks on earth. Pieces of quartz minerals with gemstone quality are also fairly common and are therefore sold for an affordable prize. In spite of the generally law prize, these noble stones possess a unique beauty with a calming effect on the mind not found in other noble stones due to the color tunes, the color variation, the luster or the clarity that these minerals show. These gemstones therefore deserve a place in any jewelry collection, regardless of the economical strength of the owner.
Quartz is composed mainly of the elements silicone and oxygen, and have the chemical formula SiO2. Pure quartz is colorless, but foreign elements can give any possible color or color pattern to a piece of a quarz mineral.
Minerals in this group can show up as 6-sided transparent crystal prisms, as translucent lumps of small corny crystals, as translucent masses composed of microscopic crystals, and as amorphous glasses with variable transparency. Crystalline quartz minerals are fairly hard, of grade 7, while grade 10 is the hardest grade possible.
These are the most important gemstone minerals in the quartz group:
Ordinary corny quartz: This form of quartz consists of myriads of small, but still visible crystals lumped together, giving large pieces of a corny appearance. This form of quartz is translucent, but not transparent. It is often white, and it is then often mistaken for marble. This variant is most often just called quartz. It can also be brown, and is then called smoke quartz. A purple or violet variant is
called rose quartz.
Aventurine: Aventurine is a rock variant mostly composed of corny quartz. In addition there are small flat grains of other minerals with a metallic shimmer, for example the crom-compound fuchsite, giving the whole stone a metallic green or blue shine. The basic color of aventurine is most often green, but it can also be orange, brown, yellow or gray.
Corny quartz can be used both as jewels in adorns and to form larger artworks.
Rock crystal: This is big and clear crystals of quartz. They are fine to form with facets like a diamond. A cut rock crystal has a unique clear transparency and a splendid luster.
Citrine: Citrine is big and transparent crystals of quartz with red, yellowish or brown colour, often due to dissolved iron. Big brown quartz crystals are also often called smoke quartz.
Amethyst: Amethyst is quartz with big crystals with a unique beautiful violet color not found in any other gemstone.
Rock crystal and the related variants like amethyst are usually used in adorns where one crystal forms one jewel.
Calcedon: A piece of calcedon consists of a myriad of microscopic crystals. Calcedon is translucent and of a uniform greyish or grey-blue color and show a calm silky luster. Calcedon is formed inside cavities by gradual crystallization from a watery solution. The center of the specimen is often still hollow, and the innermost layer often consists of rock crystal.
Agate: Agate is often concidered a variant of calcedon. A complete agate specimen consists of multiple layers of microscopic crystals, one layer inside the other. A piece of agate is translucent, but not transparent. The layers give a beautiful pattern of bands of various colors when a specimen is cut through. All colors can be present, but most common are shades of brown, red-brown, blue-brown, blue and white. An agate is formed inside cavities by gradual crystallization from a watery solution one layer inside the other. The center of the specimen is often still hollow as in calcedon, and the innermost layer often consists of rock crystal or amethyst.
Onyx: An onyx specimen consists of microscopic crystals and is composed of layers with different colors, just like an agate. But in onyx the colored bands are stacked upon each other in a more parallel regular way. All layers together tend however to form a bowed wave-like pattern. The bands are often just a few. Most colors can occur in onyx, also white and black. Blue or purple is however lacking. Jewelers often cut out pieces from areas with specific colors and use these as gemstones. When jewelers speak about onyx, they usually talk about such pieces in black or other specific colors. The term "onyx" is also used about marble-related rock types with the same pattern of stacked layers. This kind of stone which does not contain quartz minerals is extensively used in artworks.
Carneol: Also a carneol specimen consist of microscopic crystals. Carneol is deep red and nearly not translucent at all.
Specimens of calcedon, agate onyx and carneol can be rather big. These stones can therefore be used both as jewels in adorns and to make larger artworks of a pecular beauty.
Opal: Opal is physically a sort of glass with microscopic water drops blended into its structure. The water causes a diffraction and interference of the light falling onto it that make the opal show a complicated silky color play. As opal is a rare stone, it is the most precious member of the quartz group.
Obsidian: Obsidian is a glass produced when magma erupted from volcanoes is cooling. Obsidian often contains small gass bubbles, soluted coloured substances or impurities. Obsidian can be transparent, translucent or totally opaque. The color is mostly green, white or whitish, but sometimes so dark that it is nearly black.
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Knut Holt is an internet consultant and marketer. ---- To read more about gemstones, noble metals and to find affordable jewelry of high quality, please see this site:
http://www.panteraconsulting.com/salg3.htm
At this site there are information and products of a wider category, like hobby items, fashion, healh products and car equipment:
http://www.mydeltapi.com
----Free to reprint with the author's name and link.
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