TABLE OF CONTENTS Articles of General Interest - Gem Listings Reference Charts - Lapidary - Jewelry GEMOLOGY An Introduction to Gemology - Practical Gemology - Advanced Gemology Advanced Gem Information - Gemstone Grading - Appraising

GEM LISTINGS Agate Alexandrite Amber Amethyst Ametrine Ammolite Andalusite Apatite Aquamarine Assembled Stones Axenite Benitoite Chrysocolla Chalcedony Charoite Chicken-Blood Stone Citrine Diamond Danburite Emerald Fossilized Organisms Garnet Hyperitdiabas Iolite Jade Jasper Labradorite Lapis Lazuli Malachite Mali Garnet Moldavite Moonstone Morganite Black Onyx Opal Pearl, Freshwater Pearl, Saltwater Peridot Quartz Red Beryl Rubelite Ruby Sapphire Scapolite Sphalerite Sphene Spinel Sugilite Oregon Sunstone Tanzanite Tiger's Eye Topaz Tourmaline Turquoise Zircon GENERAL INTEREST Center-fused Color Treated Gemstones GIA's New Diamond Cut Grading System What you need to know about the new system. The Misconception and Erroneous Marketing of Alexandrite Verses Color Change Chrysoberyl A Consumer's Guide to Gem Grading Still more articles are in our Special Features page. PROFESSIONAL REFERENCES PROFESSIONAL GEM REFERENCE Access is restricted to members. GEM PRICING GUIDE Access is restricted to members. (Click here for a sample.) . REFERENCE CHARTS (Feel free to print these for future use.) BIRTHSTONES WEIGHTS & MEASURES MOH'S SCALE OF HARDNESS GEM STRUCTURE STANDARD GEM SIZES LAP MATERIALS ABRASIVE SIZES RING SIZE COMPARISON CHART DIAMOND AND SIMULANT COMPARISON CHART DIAMOND LOOK ALIKE COMPARISON CHART BEAD AND NECKLACE CHARTS ESTIMATING GEM WEIGHT METAL/WAX FORMULAS GEMOLOGY The Study of Gemstones Note: This is the course material for the International Gem Society's gemology course. For complete details on our gemology course, follow this link. AN INTRODUCTION TO GEMOLOGY Public Area An Introduction to Gemology First steps in learning about gems. What is a Gem? Explains just what constitutes a gemstone. Gem Formation How gems are created. The X Factor Why some gems are more common that others. Gem Cutting Terms since these are so often used to describe gems. How Gems Are Classified Mineral Habits This goes along with the above article. How Gems Are Identified An outline of the procedures. Hardness and Wearability What you need to know about the durability of your gems. Gemstone Treatment and Enhancement An introduction to a complex subject. Tools of the Gemologist What you need to advance your study. Modern Determinative Gemology A simplifed method of gem identification. 10X Loupe The Gemologists Best Friend Taking Tests PRACTICAL GEMOLOGY Members Only Area Cheat Sheets for Gemologists Disclosing Enhancements Testing Procedures The traditional method for gem identification. Determinative Gemology Modern methods for determining a gems identity. ...Difficult Separations Taking the examples one step further. What is it? A series of practical gem identification problems. Is it Worth It? A series of practical gem grading problems. Using The Refractometer A primary step in gem identification. How the RI it is measured, interpreting the results. Testing for Surface Treated Gems Specific Gravity Testing Tools and methods for determining density. Using a Polariscope Methods for determining optical axis and double refraction. The Dichroscope The Microscope The Spectroscope Ultraviolet Testing Destructive Tests Magnetism in Gemology The Forgotten Property? ADVANCED GEMOLOGY Members Only Area Your Gem Lab How to set up your gem lab The Optical Properties of Gemstones The Physical Properties of Gemstones Color Change Gems An explanation of how the phenomena works. On Seeing Red (and green) Radiation and the Treatment of Gemstones HPHT Diamond Update Identifying Inclusions ADVANCED GEM INFORMATION Members Only Area Synthetic Gemstones and Their Identification Identification of Synthetic Diamonds Phenomenal Gems Amber Amblygonite Ammolite Ammonite Aragoite Beryl Calcereous Concretions Chalcedony Clinochlore Coral More About Coral Corundum    Sapphire    Natural Rubies Clarity Enhanced With Lead Glass    Corundum Treatments Diamond Diopside Enstatite Epidote Feldspar    Species: Microline - Orthoclase - Plagioclase includes Albite, Andesine, Anothrite, Bytonite, Labradorite, and Oligioclase     Varieties: Adventurine - Adularia - Amazonite - Moonstone - Peristerite - Perthite - Sanadine - Spectrolite - Sunstone Gahnospinel Garnets 1    Understanding Garnets    Identifying Garnets Simplified Natural Glass    Man Made Glass Gypsum Laserblue Opal    The Wonderful World of Opals Pearls 1    More About Pearls Quartz Rhodonite Scapolite Shattuckite Sea Shells 1    More About Sea Shells Spinel Spodumene Includes Kunzite and Hiddenite Sugilite Topaz Tourmaline    Paraíba Tourmaline Tremolite Vivianite Zircon GEMSTONE GRADING Members Only Area General An Introduction to Grading Gems Carats, Karats and Carrots Evaluating the Cut Grading Set Stones Recutting Diamonds and Colored Stones Grading Gem Carvings Colored Stones Evaluating Color - hue, tone, and saturation Clarity Grading for Colored Stones Phenomenal Gems Diamonds Distinguishing Diamonds Clarity Grading Diamonds Color Grading White Diamonds Color Grading Fancy Colored Diamonds Cut Grading Diamonds Part I Traditional Methods Cut Grading Diamonds Part II Modern Methods Using a Reticle Help with measurements Opals Appraising Opals - Part 1, Nomenclature Appraising Opals - Part 2, Applying Value Appraising Members Only Area Appraising 1, Terminology Appraising 2, How to appraise gems and jewelry Gem Pricing Guide Jewelers Pricing Survey The Fundamentals of Lapidary Part 1, Introduction Part 2, Making Smaller Pieces Part 3, Tumbling Part 4, Cabochon Cutting Part 5, Faceting Heat Treating Procedures Jewelry FundaMetals 1 The Precious Metals FundaMetals 2 The Nomenclature of Jewelry or "What do you call that thingy?"