Search results
Results from the WOW.Com Content Network
Color: Purple, violet, dark purple: Crystal habit: 6 sided prism ending in 6 sided pyramid (typical) Twinning: Dauphine law, Brazil law, and Japan law: Cleavage: None: Fracture: Conchoidal: Mohs scale hardness: 7 (lower in impure varieties) Luster: Vitreous/glassy: Streak: White: Diaphaneity: Transparent to translucent: Specific gravity: 2.65 ...
The term porphyry is from the Ancient Greek πορφύρα (porphyra), meaning "purple". Purple was the colour of royalty, and the Roman "imperial porphyry" was a deep purple igneous rock with large crystals of plagioclase. Some authors claimed the rock was the hardest known in antiquity.
Lapis lazuli (UK: / ˌ l æ p ɪ s ˈ l æ z (j) ʊ l i, ˈ l æ ʒ ʊ-,-ˌ l i /; US: / ˈ l æ z (j) ə l i, ˈ l æ ʒ ə-,-ˌ l i /), or lapis for short, is a deep-blue metamorphic rock used as a semi-precious stone that has been prized since antiquity for its intense color.
The name sapphire is derived from the Latin word sapphirus, itself from the Greek word sappheiros ( σάπφειρος ), which referred to lapis lazuli. [2] It is typically blue, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors.
Philosopher's stone. The Alchymist, in Search of the Philosopher's Stone by Joseph Wright of Derby, 1771. The philosopher's stone [a] is a mythic alchemical substance capable of turning base metals such as mercury into gold or silver [b]; it was also known as "the tincture" and "the powder". Alchemists additionally believed that it could be ...
Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula Cu Al 6( PO 4)4( OH)8·4 H 2 O. It is rare and valuable in finer grades and has been prized as a gemstone for millennia due to its hue.
The turquoise gemstone is the namesake for the color. Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula Cu Al 6 ( P O 4) 4 (O H) 8· 4 H 2 O. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its ...
Tyrian purple (Ancient Greek: πορφύρα porphúra; Latin: purpura), also known as royal purple, imperial purple, or imperial dye, is a reddish-purple natural dye. The name Tyrian refers to Tyre, Lebanon, once Phoenicia.
Color: Purple, Yellow: Crystal habit: 6-sided prism ending in 6-sided pyramid (typical) Twinning: Dauphine law and Brazil law: Cleavage: none: Fracture: Conchoidal: Mohs scale hardness: 7: Lustre: Vitreous: Streak: white: Diaphaneity: Transparent to translucent: Specific gravity: 2.65: Optical properties: Unixal (+) Refractive index: n ω = 1. ...
Diamonds occur in a variety of colors—steel gray, white, blue, yellow, orange, red, green, pink to purple, brown, and black. [2] [3] Colored diamonds contain interstitial impurities or structural defects that cause the coloration; pure diamonds are perfectly transparent and colorless.