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Hematite (/ ˈ h iː m ə ˌ t aɪ t, ˈ h ɛ m ə-/), also spelled as haematite, is a common iron oxide compound with the formula, Fe 2 O 3 and is widely found in rocks and soils. [6] Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of Fe
The name Almandine is a corruption of Alabanda, a region in Asia Minor where these stones were cut in ancient times. Chemically, almandine is an iron-aluminium garnet with the formula Fe 3 Al 2 (SiO 4 ) 3 ; the deep red transparent stones are often called precious garnet and are used as gemstones (being the most common of the gem garnets). [ 17 ]
Psilomelane is a group name for hard black manganese oxides including hollandite and romanechite. Psilomelane consists of hydrous manganese oxide with variable amounts of barium and potassium. Psilomelane is erroneously, and uncommonly, known as black hematite, despite not being related to true hematite, which is an iron oxide.
The Gnostics wore the stone as an amulet for longevity, for wealth and courage, to strengthen the stomach, and to dispel melancholy. [6] In the Middle Ages it was considered useful for animal husbandry. [6] The ancient Greeks and Romans wore the stone to bring renown and favor, to bring endurance, and as a charm against the bite of venomous ...
Oregon Sunstone is unique in that crystals can be quite large. The copper leads to variant color within some stones, where turning one stone will result in manifold hues: the more copper within the stone, the darker the complexion. [9] On August 4, 1987, the Oregon State Legislature designated Oregon Sunstone as its state gemstone by joint ...
Four methods of nomenclature are used: [3] [5] The initial letters of a name, for example: cyanotrichite: Cya and mitscherlichite: Mits. A combination considered characteristic of the mineral name, for example: ewingite: Ewg and neighborite: Nbo. A selection of letters expressing components of the name, for example: adranosite = Arn and ...
Demantoid is the green gemstone variety of the mineral andradite, a member of the garnet group of minerals.Andradite is a calcium- and iron-rich garnet.The chemical formula is Ca 3 Fe 2 (SiO 4) 3 with chromium substitution as the cause of the demantoid green color.
The haematopoietic system (spelled hematopoietic system in American English) is the system in the body involved in the creation of the cells of blood. [ 1 ] Structure