Interesting informations about gemstones

Interesting information about jewellery stones

Gemstones

Minerals are what are generally perceived to be as beautiful as jewelry and used. The gemstones are especially precious and semiprecious stones in jewelry quality counts, but other stones such as amber, coal pitch or relatively small and beautiful fossils. The doctrine of gemstones is also called gemmology.

Auswahl verschiedener Schmucksteine. Das größte Exemplar misst etwa 40 mm

The trade includes pearls and coral to semi-precious stones. Some minerals are either too rare or too fragile to jewels to be processed (for example Leucit), but are nevertheless of collectors and museums is highly prized, although it is not one of the stones are in the true sense.

General history

Probably since the Palaeolithic find stones used as jewelry. In antiquity were gems besides gold, silver and other materials for jewelry processing. The diamond was even then the most valuable gemstones. In addition, were also emerald, ruby, sapphire and beryl known. As a gemstone was but also the use of amber.Since stones usually represent a considerable value, they were not infrequently falsified. The color of a few, cheap, to be procured minerals such as agate, was created by burning or staining changed and then "real" resold.

In ancient and medieval jewels were just some more or less polished, the facet joints was only in the early modern period on.

Minerals

Minerals in the appropriate quality are often used as a gemstone.Depending on the mineral species (for example, diamond, amber, malachite) are different criteria for determining the quality applied. Oft entscheidet die Often, the light transmission, clarity and color over the use and value as a gemstone. The precious gemstone, the diamond, you put four properties up, cut the shape, carat weight, color and purity, of which only the first of human influence can be. Some minerals have inclusions of foreign material, the value of the stone lessen, but also can increase. Also, the discovery can be a difference in the fine details of individual expression, which in turn, a specialist the origin of the stone away.

Semi-precious stones are partly the heat-treated or radioactively to their optical properties to improve or change. The color of amethyst is proposing, for example, after heat treatment from purple to yellow to. Subsequently, the treated mineral as "Topaz" in the retail market. In Germany, these artificially treated minerals to be identified accordingly.

Minerals in Jewelry quality will also be produced synthetically, such as zirconia or corundum. The quality of synthetic diamonds has in recent years greatly improved, so that some of these now also used as a gemstone can be found.

Gemstones

Selection facetted stopper forms

Urheber: Jürgen Schoner, 2005, GNU-FDL vergrößern Author: Jürgen Schoner, 2005, GNU-FDL enlarge

Gemstones are very rare minerals that are characterized by exceptional beauty and high mechanical resistance reward. What about the precious mineral is counted or not is purely a subjective perception and is directly related to the respective cultural background and the appropriate age. Well-known gems such as diamond, ruby, sapphire and emerald.

Most gemstones are now crystal-like shapes cut to the light reflection and to increase the shine, but also to the mineral an appealing form. For brilliant cut cut diamond, one speaks of diamonds. In general, polished gems and jewelry as described.

Classifications

Besides the above mentioned classification features, such as light transmittance, and color purity, there is inter alia the following criteria to the criteria of determining mineral based are:

Among the criteria used include the first chemical composition, for example, diamonds are made of carbon, rubies from chromgefärbtem alumina (Al 2 O 3). Furthermore, even after they gemstones crystal system, the type of crystal lattice distinguished, for example, cubic, trigonal or monoclinic can be. The so-called habitus, the form in which the gemstone in nature to find, is a further classification criterion.

Gem varieties are often further subdivided into different varieties: the name of the corundum is defined by its color: red corundum is ruby acted as such, a special red-orange as Padparatscha. The remaining colors in the collective brand name sapphire. Even diamonds can occur in different shades, which are then called "fancy diamond 'are known. Beryl can be found as emerald (green), aquamarine (blue), Bixbit (red), Goschenit (colorless), Heliodor (yellow) or Morganite (pink).

Physical differences manifest themselves in the refractive index, dispersion, specific density, hardness, cleavage, and the brittleness shine. Gems like alexandrite Pleochroismus can be multicolored or birefringent be. Is also characterized by their absorption spectrum.

For the value of a gemstone is its weight eventually play a significant role.

Semiprecious stones

"Semi-precious stones", a more colloquial term, in accordance with the present nomenclature no longer used, should be rare minerals that are characterized by their beauty, reward, unlike the gems but much more frequently in nature, they are usually not so hard and less valuable than that. Among the semiprecious stones "are, inter alia, alexandrite, amethyst, beryl, garnet, lapis lazuli, malachite, quartz, topaz, turquoise (mineral), zircon, hematite and pyrite in gemstone quality counted.

Classifications

The usability and the value of a "semi-precious stones" are based on criteria which are heavily dependent on the mineral species are. There are, for ores such as hematite, pyrite and no other criteria than the gloss and circumstances under which form. For grenades, quartz and other minerals are similar to precious light transmission, clarity and color play a role.