How to Grade Fancy Cut Diamonds
Fancy cut diamonds can have any finished shape, except round. These stones have their own grading criteria, in particular regarding proportion…
Online Education
For Gem Enthusiasts
- 18,327 Members
- 1,673 Articles
- 279 Gemology Businesses
Ways to Start Your Gemology Education
Join Our Thriving Community
1,673
Articles
18,327
Members
279
Directory Listings
The world's best gem articles, published weekly.
Most Recent Articles
Weloganite Value, Price, and Jewelry Information
Truly a collector’s gem, weloganite is very rare and seldom cut. This stone can show pale yellow colors.
Jewelry Nomenclature: Gem Settings
Jewelry designers and consumers can pick from many different gem settings. Learn the names and uses of common and speciality settings for any type…
Traditional Diamond Cut Grading Methods
Traditional diamond cut grading methods prepare gemologists for making evaluations with minimal time, tools, and references. This step-by-step…
Colemanite Value, Price, and Jewelry Information
Colemanite is an abundant mineral, and transparent material isn’t rare. However, gem cutters rarely facet these typically pale stones. Difficult…
Premium guides and must-read resources.
Recommended guides and resources
Gemstone Encyclopedia
Our Gemstone Encyclopedia has information on over 300 gemstones, from traditional and popular jewelry standards to collector’s stones that rarely appear for sale. Each entry has photos and detailed information about the gem’s properties. Entries for jewelry stones also have price guidelines and discussions of their most important value factors.
Emerald
Emerald has been synonymous with the color green since ancient times. A fine emerald is a truly breathtaking sight, and this member of the beryl family deserves its placement among the traditional “Big Four” gems along with diamond, ruby, and sapphire.
Onyx
For millennia, artisans have carved intricate cameos from black-and-white onyx. Solid black onyxes, faceted or cabbed, are also popular jewelry stones.
Sapphire
Few gems have held our attention over millennia as well as sapphire. The pure blue colors and excellent durability of this gem-quality member of the corundum family make for an exceptional gemstone. However, not all sapphires are blue. The September birthstone comes in every color of the rainbow (except red).
Moissanite
When it comes to engagement ring stones, there’s a lot to consider. In the moissanite vs diamond debate, we’ll look at three main factors: beauty, durability, and price.
Hematite
Hematite has a long history of use as a pigment. As a gemstone, this material is often carved but very rarely faceted. Despite its association with blood and the color red, hematite’s color can range from black and metallic gray to brownish red in thin slivers or crystals.
Diamond Cuts
We’ve compiled information on average costs and sizes for different diamond cuts and shapes at different carat weights. Learn how the different fancy cuts compare, and the pros and cons of different diamond cuts.
Moldavite
An olive to bottle-green natural glass, moldavite is a rare material popular with collectors of unusual gems as well as those interested in its formation from a meteorite impact.
Obsidian
Obsidian is the most common form of natural glass and occurs in many attractive varieties. Since prehistoric times, people have used this material to make jewelry and carvings as well as practical objects, like knives.
IGS Become Member