GO 340 Gemstones & Gemology ES 567 Gemstones of the World Dr. Susan Ward Aber, Geologist & Gemologist Emporia State University Emporia, Kansas USA http://www.emporia.edu/earthsci/amber/go340/gem.htm

Welcome to the Emporia State University introductory course on gemology and gemstones of the world. For more details about joining this course visit www.emporia.edu/earthsci/amber/go340/. If you are interested in distance learning at Emporia State University visit http://www.emporia.edu/lifelong/geninfo/index.htm.

Gemstones have intrigued us throughout history and are desired for beauty, rarity, durability, tradition, and portability. Some believe minerals and gems possess magical powers, which accounts for their reputation as symbols of wealth, power, healing, and love. This course will not emphasize the magic, but will give an introduction to gems and gemology. Gemology is a branch of mineralogy that is concerned with the study of gem materials, including identification and testing methods, cutting and polishing, synthetically manufactured gems, precious metals and alloys, sources and origins, and grading and appraising.

Some of the topics covered are:

• A little history of gems and gemology... What is gemology? What are gemstones and the factors affecting their value? How are gems classified?
• Origin and occurrence... What are the major mineral groups and rock types that produce gem quality materials?
• Crystal chemistry... What is chemical composition and classification?
• Crystal structure... How can diamond and graphite both be composed of carbon and be different minerals? What are crystal systems?
• Physical properties... Why is diamond the hardness known substance on Earth yet easily broken?
• Visual properties... Why do some gems look like a cat's eye or have rayed stars visible?
• Testing... Instruments to positively identify different gemstones include refractometer, polariscope, diamond meter.
• Gem creation and enhancement... What is the difference between an imitation and a synthetic, heat treatment and dying?
• Fashioning... How do they cut those tiny flat facets?!?

Interested? Begin the adventure with the now!

This page originates from the Earth Science Department at Emporia State University, Emporia, Kansas, USA. For more information contact saber@emporia.edu,Susie Ward Aber. Gemstones & Gemology was created April 7, 1999 and last updated January 8, 2010.

© 1999-2010, Susan Ward Aber. All rights reserved.