EOSC 118- Midterm Exam Guide - Comprehensive Notes for the exam ( 54 pages long!)

• School: UBC
• Department: Earth and Ocean Sciences
• Course: EOSC 118
• Professor: David Turner

Document Summary

Venezuela, zimbabwe, cote d"ivoire, guinea, sierra leone, liberia, ghana. No: venezuela produces approximately 200,000 carats of rough diamond per year. How long would it take the diavik mine in northern canada to produce an equivalent amount: what are a few of the main trends outlined in this review of the kimberley. Describe the three main mechanisms of colour generation for gems. Principle: chromium in emerald because cr substitutes for the only +3 cation in base formula, al. Chromophore: an element responsible for colouration of a mineral: usually o(cid:374)e of the tra(cid:374)sitio(cid:374) ele(cid:373)e(cid:374)ts (cid:894)i. e. fe, ti, cu (cid:895) Describe the optical effects of asterism, chatoyancy, iridescence and labradorescence. Asterism: prominent star shape that normally occurs as a six pointed star: due to crystallographically oriented mineral inclusions in host mineral, best (cid:272)ut as (cid:862)(cid:272)a(cid:271)o(cid:272)ho(cid:374)s(cid:863) (cid:894)i. e. sapphires a(cid:374)d ru(cid:271)ies(cid:895) Chatoyancy: result of many fine fiber inclusions oriented in a parallel manner producing the well-k(cid:374)ow(cid:374) (cid:862)(cid:272)at"s eye(cid:863) effe(cid:272)t: best (cid:272)ut as (cid:862)(cid:272)a(cid:271)o(cid:272)ho(cid:374)s.