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Orthorhombic crystal system. In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base ( a by b) and height ( c ), such that a, b, and c are ...
Moissanite ( / ˈmɔɪsəˌnaɪt /) [5] is naturally occurring silicon carbide and its various crystalline polymorphs. It has the chemical formula SiC and is a rare mineral, discovered by the French chemist Henri Moissan in 1893. Silicon carbide or moissanite is useful for commercial and industrial applications due to its hardness, optical ...
Prehnite is an inosilicate of calcium and aluminium with the formula: Ca 2 Al(AlSi 3 O 10)(OH) 2 with limited Fe 3+ substitutes for aluminium in the structure. Prehnite crystallizes in the orthorhombic crystal system, and most often forms as stalactitic, botryoidal, reniform or globular aggregates, with only just the crests of small crystals showing any faces, which are almost always curved or ...
This is a list of gemstones, organized by species and types. Minerals. There are over 300 types of minerals that have been used as gemstones. Such as:
Crocea Mors [ fr], formerly the sword of Julius Caesar, captured by Nennius according to the legends presented by Geoffrey of Monmouth. Cruadh-Chosgarach, the Hard Destroying One, sword of Caílte mac Rónáin. Cruaidín Catutchenn, the sword of Cú Chulainn. Dyrnwyn ( White-Hilt ), the Sword of Rhydderch Hael.
Gemstone. Group of precious and semiprecious stones—both uncut and faceted—including ( clockwise from top left) diamond, uncut synthetic sapphire, ruby, uncut emerald, and amethyst crystal cluster. A gemstone (also called a fine gem, jewel, precious stone, semiprecious stone, or simply gem) is a piece of mineral crystal which, when cut or ...
Mordenite is a zeolite mineral with the chemical formula, ( Ca, Na 2, K 2) Al 2 Si 10 O 24· 7 H 2 O. and it is one of the six most abundant zeolites and is used commercially. [3] It was first described in 1864 by Henry How. He named it after the small community of Morden, Nova Scotia, Canada, along the Bay of Fundy, where it was first found.
Chrysoberyl. The mineral or gemstone chrysoberyl is an aluminate of beryllium with the formula Be Al 2 O 4. [5] [6] The name chrysoberyl is derived from the Greek words χρυσός chrysos and βήρυλλος beryllos, meaning "a gold-white spar". Despite the similarity of their names, chrysoberyl and beryl are two completely different ...