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A study of Chinese peridot gem samples determined the hydro-static specific gravity to be 3.36 . The visible-light spectroscopy of the same Chinese peridot samples showed light bands between 493.0–481.0 nm, the strongest absorption at 492.0 nm. [14]
Gem identification is basically a process of elimination. Gemstones of similar color undergo non-destructive optical testing until there is only one possible identity. Any single test is nearly always only indicative. For example: The specific gravity of ruby is 4.00, glass is 3.15–4.20, and cubic zirconia is 5.6–5.9 . So one can easily ...
Spodumene is a pyroxene mineral consisting of lithium aluminium inosilicate, Li Al(Si O 3) 2, and is a commercially important source of lithium.It occurs as colorless to yellowish, purplish, or lilac kunzite (see below), yellowish-green or emerald-green hiddenite, prismatic crystals, often of great size.
Aquamarine is a pale-blue to light-green variety of the beryl family, [2] with its name relating to water and sea. [3] The color of aquamarine can be changed by heat, with a goal to enhance its physical appearance (though this practice is frowned upon by collectors and jewelers). [4]
Jasper breaks with a smooth surface and is used for ornamentation or as a gemstone. It can be highly polished and is used for items such as vases, seals, and snuff boxes. The density of jasper is typically 2.5 to 2.9 g/cm 3. [4] Jaspillite is a banded-iron-formation rock that often has distinctive bands of jasper.
Taaffeite (/ ˈ t ɑː f aɪ t /; BeMgAl 4 O 8) is a mineral, named after its discoverer Richard Taaffe (1898–1967) who found the first sample, a cut and polished gem, in October 1945 in a jeweler's shop in Dublin, Ireland. [4] [5] As such, it is the only gemstone to have
The specific gravity is 3.4 and the Mohs hardness is 6 + 1 ⁄ 2. The name "vesuvianite" was given by Abraham Gottlob Werner in 1795, because fine crystals of the mineral are found at Vesuvius; these are brown in color and occur in the ejected limestone blocks of Monte Somma .
The pleochroism is strong, the hardness is 5–6, and the specific gravity is 3.4–3.9. On certain surfaces it displays a brilliant copper-red metallic sheen, or schiller, which has the same origin as the bronzy sheen of bronzite, but is even more pronounced. Like bronzite, it is sometimes cut and polished as a gemstone. [1]