GEOL 102 Lecture Notes - Lecture 16: Opal, Australia Women'S National Basketball Team, Birthstone

• School: Queen's University
• Department: Geological Sciences and Geological Engineering
• Course: GEOL 102
• Professor: Ronald C Peterson

Document Summary

Not a normal gemstone in terms of transition of light and faceting. Different optical behavior: overkill to put diamonds around opals. Roman rule, cleopatra, etc: found in europe, mentioned in shakespeare"s plays and sonnets. Birthstone for october: thought to have magical powers. If you wear an opal ring and you"re not born in october, it"s bad luck. The romans and the rest of the world got their opals from a mine ni dubnik, located in eastern. Largest opal found there was a rumored 2500 carats. Prior to 1930 - opals were from europe. Can be colored or uncolored on its own: uncolored = potch, continuum of color ranging. Common opal: doesn"t interact with light = potch. Black opal: most famous: translucent to opaque, found in australia, black body colour caused by suspended impurities: great color on a black matrix. Crystal opal: second most valuable: clear, translucent, play of color against clear body colour, more valuable than white.