GEOLOGY G130	GEMSTONES	GMC


	Course Outline

  I. 	INTRODUCTION

	A.	Geology as a Science

		1.	What geology is

		2.	Relationship to other sciences

		3.	Gemology
	

	B.	Gem Materials

		1.	Definition

		2.	Organic material

		3.	Synthetic

		4.	Simulant

		5.	Mineral

			a.	Definition

			b.	Natural gemstones are all minerals

			c.	Factors controlling which mineral forms

			d.	Chemical groups

		6.	What is a rock?

 II.	COLORED GEMSTONES

	A.	Gemstone

	B.	Value Factors

		1.	Beauty


		2.	Rarity (4 C's)

			a.	Color

			b.	Clarity

			c.	Carat Weight

			d.	Cut

		3.	Durability

			a.	Hardness

			b.	Toughness

			c.	Stability

		4.	Demand

		5.	Tradition

		6.	Portability

	C.	Gemstone Classifications

		1. Terminology

			a.	Group

			b.	Species

			c.	Variety

		2.	Beryl

		3.	Corundum

		4.	Garnets

5. Quartz

III.	DIAMONDS

	A.	Mineral

		1.	Crystal class

		2.	Chemical group

		3.	Physical and optical properties

		3.	Largest diamond

	B.	Production and marketing

	C.	Four C's

		1.	Cut

		2.	Carat weight

		3.	Color

			a.	Three factors
				1)  brilliance
				2)	 dispersion
				3)  body color

			b.	Color grading

		4.	Clarity


 IV.	CUTTING AND POLISHING (handout only)

  V.	IDENTIFICATION OF GEMSTONES

	A.	General Observation

		1.	Uses

		2.	Color
	
		3.	Transparency

		4.	Cut

		5.	Phenomena

		6.	Luster

		7.	Dispersion

		8.	Heft

		9.	Assembled Stones

	       10.	Fracture and Cleavage

	B.	Refractometer

	C.	Magnification

	D.	Polariscope

	E.	Dichroscope

	F.	Spectroscope 

	G.	Specific Gravity

	H.	Ultraviolet Fluorescence

	I.	Auxiliary Tests

  VI.	LIGHT

	A.	Nature of Light

	B.	Two basic sources of light

		1.	Incandescence
		
		2.	Luminescence

	C.	Ordinary light and polarized light
		
	D.	Reflection and refraction

	E.	Pleochroism

	F.	Luster

	G.	Transparency

	H.	Dispersion (fire)

	I.	Scintillation (sparkle)

	J.	Brilliance

	K.	Phenomena (slide lecture with handout)




VII.	MODES OF FORMATION

	A.	Classes of rocks

		1.	Igneous

			a.	Extrusive

			b.	Intrusive
				1)	 Pegmatic dikes
				2)	 Vein deposits
				3)	 Basic igneous rocks

		2.	Metamorphic

			a.	Contact metamorphism

			b.	Regional metamorphism

		3.	Sedimentary

			a.	Description

			b.	Secondary deposits

				1)  Definition
				2)  Versus primary deposits

		4.	Additional Modes of Formation

			a.	Hydrothermal

			b.	Meteoric

			c.	Organic

	B.	Ranking of gemstone sources by mode of formation

	C.	Important gemstone sources

	D.	Mining Methods

		1.	Alluvial Deposits and River Gravels

		2.	Pegmatite Dikes

		3.	Opals (primarily Australia)


VIII. GEMSTONE ENHANCEMENTS (video with handout)

IX.	GEMSTONES OF AMERICA (video with handout)

X.	DIAMOND SIMULANTS, SYNTHETIC PROCESSES AND ASSEMBLED STONES
	 (slide lecture with handouts)