Geol. 115 Study Guide for Lesson Eight

What do you need to know (meaning understand, not just memorize) to do spectacularly well on Quiz 8? The essential terms and concepts are listed below. Writing out answers to each of the following would be an excellent way to prepare.

(Be able to define or recognize the definition of these terms and understand their useage in context). You can find the information in the web lesson -- on your test, do not expect exactly the same wording or examples as in your lesson. It would be a good idea to cross reference the defintions in the lesson with those you find in the texts.)

1) Essential Vocabulary

Enhancement, FTC, AGTA, enhancement code, "sun spangles", quenching, discoid stress fractures, annealing, HPHT process, prasiolite, "precious topaz", pinking, "green Tanzanite", "Maxixe" beryl, "oro verde" quartz, Kunzite, Hiddenite, A, B and C jadeite, quench crackling, carbonization, impregnation/stabilization, oiling/filling, the flash effect, surface diffusion, bulk or lattice diffusion, beryllium, foilback, rhinestone, "Mystic" topaz.

2) Essential Concepts

Definition of enhancement, why the enhancement status of a gem matters, role of FTC and AGTA in regards to gem enhancement, continuum of knowledge with regard to gem enhancement, 2 general and 12 specific enhancement codes used by AGTA (symbol, what it means, examples of gems), general history of enhancement of gems, for each of the major gem enhancement categories (heating, irradiation, dyeing, etc.), know how it is done, which gems are most commonly treated, effect of treatment, effect on value, if this enhancement can be detected, how? Importance of heating/cooling regimen and heating atmosphere to outcome: examples. New enhancement processes (HPHT for diamonds, bulk diffusion for corundum). The difference between "unheated" and "unenhanced". Strategies for determining enhancement status in various types of gems ex: how would you determine if a blue diamond was irradiated or natural color, how would you tell if a pearl was dyed or irradiated, etc. Name some gems which are always treated, name some which we can presently assume are never treated. What are the degrees of treatment for jade (A, B, C). Be able to give examples where enhancements have little to no effect on the price certain gems, and those which affect the price greatly. Which enhancements make a gem more stable, which make it more fragile. General guidelines for care of enhanced gems.

3) Pronunciation Guide

(Clicking on the term will temporarily take you to a new web page to hear the pronunciation of the word. Depending on your browser configuration either put away the audio window, or use the back button to return to the list.)

Beryl, discoid fracture, limonite, annealing, prasiolite, zoisite, Goshenite, "Maxixe", oro verde, scapolite, spodumene, padparashah, beryllium.