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Peridot (/ ˈ p ɛ r ɪ ˌ d ɒ t,-ˌ d oʊ / PERR-ih-dot, -doh), sometimes called chrysolite, is a yellow-green transparent variety of olivine.Peridot is one of the few gemstones that occur in only one color.
Calcite. Manganoan calcite (var.); Caledonite; Canasite; Cancrinite. Vishnevite; Carletonite; Carnallite; Cassiterite; Catapleiite; Cavansite; Celestite; Ceruleite ...
Many gems are crystals which are classified by their crystal system such as cubic or trigonal or monoclinic. Another term used is habit, the form the gem is usually found in. [12] For example, diamonds, which have a cubic crystal system, are often found as octahedrons. [13] Gemstones are classified into different groups, species, and varieties.
One test to determine the gem's identity is to measure the refraction of light in the gem. Essentially, when light passes from one medium to another, it bends. Blue light bends more than red light. How much the light bends will vary depending on the gem mineral. Every material has a critical angle, above which point light is reflected back ...
Main jade producing countries. Jade is an umbrella term for two different types of decorative rocks used for jewelry or ornaments.Jade is often referred to by either of two different silicate mineral names: nephrite (a silicate of calcium and magnesium in the amphibole group of minerals), or jadeite (a silicate of sodium and aluminum in the pyroxene group of minerals). [1]
In the wholesale trade of gem diamonds, carat is often used in denominating lots of diamonds for sale. For example, a buyer may place an order for 100 carats (20 g) of 0.5-carat (100 mg), D–F, VS2-SI1, excellent cut diamonds, indicating a wish to purchase 200 diamonds (100 carats (20 g) total mass) of those approximate characteristics.
Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sapphires. Ruby is one of the traditional cardinal gems, alongside amethyst, sapphire, emerald, and diamond. [3] The word ruby comes from ruber, Latin for red. The color of a ruby is due to the element chromium.
For gem identification purposes, a pick-up response to a strong neodymium magnet separates garnet from all other natural transparent gemstones commonly used in the jewelry trade. Magnetic susceptibility measurements in conjunction with refractive index can be used to distinguish garnet species and varieties, and determine the composition of ...