Physical and Optical Properties of Gemstones
Learn about gemstone color, crystallography, hardness, chemical makeup and more.
Quartz Toxicity: Understanding the Risks for Jewelers and Wearers
Understand quartz toxicity: safe for jewelry wearers but potentially dangerous for makers. Learn about silica dust health risks, essential safety...
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How Old Is My Zircon?
Is zircon the oldest mineral? Find out why zircon is important for scientifically dating rocks and how to learn a...
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Turquoise Color and the Color Turquoise
Is all turquoise turquoise color? Learn about this gem's most popular natural colors and how people have prized them for...
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Turquoise Care Guide
Beautiful turquoises tend to show wear over time. Our turquoise care guide will show you the best ways to clean...
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Jade Toughness and Care
Jade toughness is legendary. However, this gem isn’t indestructible. Learn what makes jadeite and nephrite so tough and how to...
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Gemstone Optics: The Basics
Accurately measuring optical properties is critical for identifying gemstones. This article covers the basic terminology and concepts of gemstone optics....
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Gemstone Optical Properties
Learn how gemstone optical properties, like refractive index and pleochroism, help gemologists identify gems and lapidaries choose cuts.
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What is Gemstone Cleavage?
Gemstone cleavage is a break in a crystal along internal planes. Learn the science behind this and the difference between...
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Descriptive Crystallography for Gemologists
Crystallography is the study of crystalline solids. Learn the most common terms gemologists use to describe the structure of crystal...
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Gemstone Color Measurements and Specifications
Gemstone color measurements are hard to make with conventional color-order systems. Learn how recent colorimetry tech advances have improved accuracy....
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Gemstone Color Change Phenomena
Why do certain gems change color under different lights? Explore gemstone color change phenomena and the difference between natural and...
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What are Allochromatic and Idiochromatic Gems?
Learn the difference between allochromatic and idiochromatic gems and why some gem species can occur in many color varieties and...
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Phenomenal Gems: Cat’s Eyes, Star Stones, and More
Phenomenal gems seem to do magical things with light. Learn the science behind optical effects like cat’s eyes and star...
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Gemstone Physical Properties
The optical properties of gems attract our eyes and can give a cut stone a unique character. However, gemstone physical...
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What are Gemstone Enhancements?
Gemstone enhancements improve the appearance and wearability of gems. Learn about the most commonly used procedures and frequently treated types...
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Gemstone Thermal Properties
Non-destructive tests are critical for gemologists trying to identify gems. Learn how measuring thermal properties, especially thermal inertia, can help....
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What is Gemstone Pleochroism?
Some gems show pleochroism, two or three different colors depending on the viewing angle. Learn why this occurs and how...
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Gemstone Magnetism: The Forgotten Property
Although gemstone magnetism isn't commonly tested, it can help gemologists distinguish similar looking gems. Learn how to analyze this property....
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What is a Trapiche Emerald?
Trapiche emerald gems are some of the world's rarest emeralds. Learn where they're found and how their characteristic “spoked wheel”...
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What is Gemstone Luminescence?
Gemstone luminescence is a glow that occurs when certain stones are subjected to energy such as UV light. This effect...
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Evaluating Gem Color: Hue, Tone, and Saturation
Accurately describing gem color is critical to determining a gemstone's value. Learn how to grade hue, tone, and saturation and...
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Understanding Color in Gemology
The color of a mineral or gemstone is one of the primary attributes used for identification,but it is, unfortunately, one...
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