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Jet as a gemstone became fashionable during the reign of Queen Victoria. [46] It originally became fashionable in the 1850s after the queen wore a necklace of it as part of mourning dress for Princess Victoria of Saxe-Coburg and Gotha. [46] Later the Queen wore Whitby jet as part of her mourning dress while mourning the death of Prince Albert.
Carnelian (also spelled cornelian) [3] is a brownish-red mineral commonly used as a semiprecious stone.Similar to carnelian is sard, which is generally harder and darker; the difference is not rigidly defined, and the two names are often used interchangeably.
Phyllite Photomicrograph of thin section of phyllite (in cross polarised light) Fractured Duke stone showing phyllitic texture Phyllite. Phyllite (/ ˈ f ɪ l aɪ t / FIL-yte) is a type of foliated metamorphic rock formed from slate that is further metamorphosed so that very fine grained white mica achieves a preferred orientation. [1]
This is a list of gemstones, organized by species and types. Minerals There ... Eilat stone; Epidosite; Glimmerite; Goldstone (glittering glass) Hawk's eye;
Nephrite jade is an ornamental stone used in carvings, beads, or cabochon cut gemstones. Nephrite is also the official state mineral of Wyoming . Nephrite can be found in a translucent white to very light yellow form which is known in China as mutton fat jade, [ 1 ] in an opaque white to very light brown or gray which is known as chicken bone ...
As a general rule, a cut gemstone will reduce the mass (in carats) by about 50%. [1] Among the several techniques used to work with gemstones are sawing, grinding, sanding, lapping, polishing, grilling, and tumbling. The diamond cut planning stage is a complex process that requires the cutter to work with unique rough stones.
The adjective porphyritic now refers to a certain texture of igneous rock regardless of its chemical and mineralogical composition or its color. Its chief characteristic is a large difference in size between the tiny matrix crystals and the much larger phenocrysts.
In computer graphics, a procedural texture [1] is a texture created using a mathematical description (i.e. an algorithm) rather than directly stored data. The advantage of this approach is low storage cost, unlimited texture resolution and easy texture mapping . [ 2 ]