Diamond (gemstone) Diamond (gemstone) A diamond (from the "adámas", meaning "unbreakable", "proper", or "unalterable") is one of the best-known and most sought-after gemstones. Diamonds have been used as decorative items since ancient times; some of the earliest references can be traced to 25,000 - 30,000 B.C. The hardness of diamond and its high dispersion of light—giving the diamond its characteristic "fire"—make it useful for industrial applications and desirable as jewelry. Diamonds are such a highly traded commodity that multiple organizations have been created for grading and certifying them based on the "four Cs", which are color, cut, clarity, and carat. Other characteristics,
Volcanic Rock (album) Volcanic Rock (album) Volcanic Rock is the second studio album by Australian proto-heavy metal band Buffalo, recorded and originally released in 1973 on the Vertigo label. The album was stylistically a much harder, heavier and rawer release than its predecessor ("Dead Forever...") – marking a move away from the band's previous progressive rock influences, although retaining a psychedelic element to their sound. "Volcanic Rock" had been recorded effectively as a live-in-the-studio effort, with only vocal and additional guitar overdubs added later during the recording sessions. The album courted controversy with its cover artwork upon its release. Illustrated by J. Phillip