Search results
Results from the WOW.Com Content Network
Charoite (/ tʃæroʊ.aɪt / CHAR-ow-ait) is a rare silicate mineral with the chemical composition K (Ca,Na)2Si4O10(OH,F)•H2O, first described in 1978. It is named after the Chara River, despite its being 70 kilometres (43 mi) away from the discovery place. [ 6 ][ 3 ] When it was discovered, it was thought to be a fake, dyed purple to give it ...
Rhodolite. Rhodolite is a varietal name for rose-pink to red mineral pyrope, a species in the garnet group. It was first described from Cowee Valley, Macon County, North Carolina. [2] The name is derived from the Greek "rhodon" for "rose-like", in common with other pink mineral types (such as rhodochrosite, rhodonite).
Amethyst is a purple variety of quartz (SiO. 2) and owes its violet color to irradiation, impurities of iron (Fe3+. ) and in some cases other transition metals, and the presence of other trace elements, which result in complex crystal lattice substitutions. [2][3][4] The irradiation causes the iron Fe3+.
Pleochroism. Present, dichroism or trichroism, depending on heat treatment. Tanzanite is the blue and violet variety of the mineral zoisite (a calcium aluminium hydroxyl sorosilicate), caused by small amounts of vanadium. [3] Tanzanite belongs to the epidote mineral group. Tanzanite is only found in Simanjiro District of Manyara Region in ...
Saw-cut and polish—Stones up to 1/2 kg are cut with diamond saws into thin slabs, which then are cut into various shapes. One side of the shaped slab is polished producing fine jewelry pieces and collectible gems called cabochons. (Note the value of large Lake Superior agates, which weigh a few pounds or more, will lose most of their value if ...
Specialty. Dermatology, hematology. Purpura (/ ˈpɜːrpjʊərə / [1]) is a condition of red or purple discolored spots on the skin that do not blanch on applying pressure. The spots are caused by bleeding underneath the skin secondary to platelet disorders, vascular disorders, coagulation disorders, or other causes. [2]
The name jadeite is derived (via French: jade and Latin: ilia [6]) from the Spanish phrase "piedra de ijada" which means "stone of the side". The Latin version of the name, lapis nephriticus , is the origin of the term nephrite , which is a different mineral that also shares the common name jade .
The English name of the stone is derived from Middle French hématite pierre, which was taken from Latin lapis haematites c. the 15th century, which originated from Ancient Greek αἱματίτης λίθος (haimatitēs lithos, "blood-red stone"). Ochre is a clay that is colored by varying amounts of hematite, varying between 20% and 70%. [8]