Commonly used charts for gemology and jewelry and lapidary.

moissanites in infinity setting - diamond simulants
Properties of Diamond Simulants

Diamond simulants, like cubic zirconia and moissanite, often appear in jewelry. See how the properties of real diamonds compare with popular imitations.

Diamond Look-alike Comparison Chart

Distinguishing a diamond look-alike from the real thing can be challenging. Learn how to use specific gravity and birefringence to make simple separations.

gem weight - brooch
How to Estimate Gem Weight in a Jewelry Setting

Removing and resetting a jewelry stone to weigh it is rarely worthwhile. Learn how to estimate gem weight by determining its volume with simple formulas.

Gem Structure Chart

A gem structure chart that shows various information on a specific structure and gems of example. Details include Refractive Indexes, Pleochroism and etc.

opal earring - gemology cheat sheets
Gemology Cheat Sheets

These gemology cheat sheets review gem color and clarity grading, specific information on evaluating diamonds and opals, and basic gem identification tests.

List of False or Misleading Gemstone Names

A list of False or Misleading Gemstone Names and its Actual Gemological Name. Gathered by the source "Gemstones of the World, 3rd Edition, Walter Schumann.


Jewelers need to know how to determine how much gold is needed for a wax mold. Here are three methods for you.Information and tips on metal or wax formulas.

Select Gems Ordered By Density

Select Gems Ordered By Density from the International Gem Society (IGS). Details on density and gemstones available.

Mohs hardness scale - tools
The Mohs Hardness Scale and Chart for Select Gems

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

Standard Gem Sizes Chart

Will your gem fit in a standard setting? Use this chart of standard gem sizes for popular cuts and also learn how to estimate gem weight based on size.

crystal system - tetragonal wulfenite
Table of Gems Ordered by Crystal System

This table contains a selection of minerals gemologists may encounter as jewelry stones or gem specimens. The gems are sorted by their crystal system.

spinel - gemstone refractive indices and double refraction
Table of Refractive Indices and Double Refraction of Selected Gems

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

Weights and Measures Conversion Chart

Printable chart to convert weights and measures including Carats, Grams, Kilograms, Ounces, Pounds and Troy Ounces Pounds and Pennyweights.

birthstone chart by month
Birthstone Chart

Birthstones listed by month. Also listed are both the Modern Birthstones and the Ancient Birthstones.

step square crocoite - gemstone toxicity table
Gemstone Toxicity Table

This gemstone toxicity table rates 280+ gems based on their composition and potential for bioactivity and also describes the hazards they pose.