GEOL 102 Final: GEOL 102 Gemstones Overview

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

Document Summary

Concentric layers of nacre plates deposited on a foreign particle. Thicker aragonite layers produce = reds & greens. Color pearls have a core that"s (cid:271)een (cid:272)oated. Color comes from diffraction and interference of diff. wavelengths of light. Teeth of animals (elephant tusk), mostly the dentin. Geothermal gradient: high pressure and temperature (50 000 atm, 1500 c) Hard rock mine: kimberlite pipe (crush, centrifuge, fluoresce) Often included and cracked impregnate with polymers. Heating removes brown to make it more rich blue (v3+ v4+) Sedimentary rock fractured under pressure, dilute solution carries minerals (cr, va, be) essential for emerald formation. Shaft mining: found in calcite veins in dark soft shale. Often carved instead of faceted (used for color) Lode gold: high grade, follows cracks in granite veins underground, deposits in vein w/ quartz. Erosion: bits get washed into riverbeds form nuggets. Hot spring fluids deep in earth come up and bring cu, al, P conveyer of fluids to cool and fill cracks.