Weights and Measures Conversion Chart

Refractive indices and double refraction (birefringence) help gemologists identify gems. The following table lists these values for selected gemstones.

Jewelers need to know how to determine how much gold is needed for a wax mold. Here are three methods...

Emeralds from different sources can vary in quality. Learn how to identify emerald origins by analyzing the optical and physical...

The Mohs hardness scale measures a mineral's resistance to scratching. Find the traditional scale here and a chart of select...

As Mogok, Myanmar prepares to celebrate its 800th anniversary, the inhabitants of this prolific gem producing region face an uncertain...

What’s the average gemstone faceting yield from a single piece of rough? Learn how to estimate how much material you’ll...

Pyroxmangite grains are rare, seldom clean enough to facet, and difficult to cut. However, when cut, they are extremely beautiful...

Gemologists can separate natural emeralds from emerald simulants and synthetics. Learn about the most common tools and techniques for this....