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Ruby:
Simple Oxides (Aluminum oxide) Al3O3 AKA: Corundum |
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System: Hexagonal; sometimes tapering prismatic; also pyramidal, tabular; often striated. Appearance: Deep red, blood-red; vitreous, adamantine; streak white. Physical Properties: Hardness: (9.0); Specific gravity: (3.9 - 4.1). Cleavage: None; often conspicuous parting in three directions. Fracture, uneven, conchoidal; transparent to translucent; fluorescent; brittle. Similar species: Feldspars. The fine striations on parting faces might lead to confusion with the plagioclase feldspars, but corundum may be recognized by its superior hardness and high gravity. Occurrence: Corundum forms in several distinctive environments. It occurs associated with albite and acmite in nepheline syenite pegmatites; with andalusite and cordierite in hornfels of contact metamorphic rocks; and with muscovite, almandine and oligoclase in gneiss and hornfels of metamorphic terrains. Gem quality ruby has only been found in a few places in North America, primarily North Carolina. Thailand, Ceylon and Burma are the principle sources for ruby. Miscellaneous: Ruby is the rarest and most valuable gemstone. The highest value is based on its clarity, though it may contain bundles of tubelike inclusions, giving "star" or "cats eye" effect in cut or polished stones. Some rubys are faceted, but most are worked into cabochons. The name is from kuruntam, a Tamil word derived from Sanskrit kuruvinda, "ruby". Ruby is the birthstone for July. Conventional Wisdom: Ruby is known as a stone of nobility, gathering and amplifying energy while promoting and stimulating mental concentration. It can improve ones success in controversies and disputes, encouraging gentleness and discouraging violence. It is an excellent shielding stone, protecting on all levels and safeguarding ones consciousness from psychic attack. Belongs to the Astrological Signs of Leo, Scorpio, Cancer and Sagittarius. |