Today's jewelry is modified by minerals called gemstones. Amber and Jet are in the family of the mineral, but are not used for jewelry. Most gems originally possess a hard, rough surface, but are then made slick so that their aesthetic value is higher. The stones were used as antiques in the 19th century. The Greeks closely cherished these as valuables.
Precious and semi-precious were both specific classifications made by the Ancient Greeks for the gems. The phrase 'hard stones' was used in the history and archaeology of the material. Precious gems such as rubies, emeralds, diamonds, and sapphires are still used as adornments today. Many different stones other than these, are classified by color, surface density, and transparency.
They are also made of many chemical compositions. This is called the crystal system; it includes cubic, monoclinic, and trigonal. Habit is the term that identifies the original form of the material. Its habit is changed once the gemstone is prepared to be constructed artificially. First, second and third water are the gem's levels of transparency from greatest to least.
The Gemological Institute of America has developed grading systems for the stones, first in 1950. Color, cut, carat, and clarity were the standards used for grade. Gems were graded with the naked eye until the institute came up with a magnifier, which instilled more clarity. After this invention, a person could see up to ten times better for grading.
Physical characters that make the value of colored gems are asteria and color zoning. Uneven color distribution inside of a stone is known as color zoning. Asteria is the 'star effect'. Greeks highly valued asteria for the fact that they were 'love' gems.
The other processes to making gemstones artificial are cutting, polishing, heat treatment, fracture treatment, waxing, oiling.
Precious and semi-precious were both specific classifications made by the Ancient Greeks for the gems. The phrase 'hard stones' was used in the history and archaeology of the material. Precious gems such as rubies, emeralds, diamonds, and sapphires are still used as adornments today. Many different stones other than these, are classified by color, surface density, and transparency.
They are also made of many chemical compositions. This is called the crystal system; it includes cubic, monoclinic, and trigonal. Habit is the term that identifies the original form of the material. Its habit is changed once the gemstone is prepared to be constructed artificially. First, second and third water are the gem's levels of transparency from greatest to least.
The Gemological Institute of America has developed grading systems for the stones, first in 1950. Color, cut, carat, and clarity were the standards used for grade. Gems were graded with the naked eye until the institute came up with a magnifier, which instilled more clarity. After this invention, a person could see up to ten times better for grading.
Physical characters that make the value of colored gems are asteria and color zoning. Uneven color distribution inside of a stone is known as color zoning. Asteria is the 'star effect'. Greeks highly valued asteria for the fact that they were 'love' gems.
The other processes to making gemstones artificial are cutting, polishing, heat treatment, fracture treatment, waxing, oiling.
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