Grading Gemstones and Diamonds

Learn how gemologists evaluate color, clarity, cut, and carat for gem grading. Consumers can use this information to find the...

Gem carvings are judged on material, workmanship, and artistry. Learn how to apply these criteria to a piece with our...

In recent decades, something remarkable invaded the thinking process of the colored stone industry. From dealers to consumers, they all...

Mastering clarity grading diamonds takes a lot of experience. This grading guide, with definitions, images, and examples, can help beginning...

First-time buyers may not understand how diamond rating works. Our guide will teach you how diamonds are graded, so you...

Distinguishing diamonds from their lookalikes requires educated eyes. Learn what visual features to look for and the properties of many...

The GIA modern diamond cut grading method is the most widely accepted in the industry. Our step-by-step guide covers the...

Fancy cut diamonds can have any finished shape, except round. These stones have their own grading criteria, in particular regarding...

Traditional diamond cut grading methods prepare gemologists for making evaluations with minimal time, tools, and references. This step-by-step guide covers...

Don't underestimate the importance of clarity, one of the Four Cs of gemstone grading. For faceted gems, basic clarity grading...

Gems in jewelry settings can't be evaluated the same way as loose stones. These guidelines are for gemologists learning to...

How goes gemstone grading work? Learn how gemologists evaluate both diamonds and colored gems and the qualities they examine.

Judging gemstone value is complex, and new gemologists can have trouble with this. These four exercises can help you learn...

Carats are the units used to measure gem weight and one of the main factors in gem grading. Learn what...

Our indicolite buying guide can help you learn how these blue tourmalines are graded, what to avoid, and how to...

Our rubellite buying guide can help you learn how rubellites are graded, what to avoid, and how to identify a...

Rare chrome tourmaline can show an emerald-like green color. With a highly desired color and tourmaline's excellent qualities as a...

The color grading standards for white diamonds don't apply to fancy colored diamonds. Learn the GIA and Argyle grading systems...

Looking for a tourmaline jewelry stone? If you like green and you're on a budget, green tourmaline or verdelite is...

How does the GIA diamond cut grading system work? Our guide will explain what the grades mean and how gemologists...

The effects of the 2014 scandal over diamond overgrading at EGL labs are still emerging. Learn what gemologists and retailers...

The US Federal Trade Commission (FTC) can help jewelry marketers avoid making deceptive claims. Learn about the FTC diamond jewelry...

Blockchain tech can provide secure, digital transaction records. Can blockchain diamonds resolve ethical and legal issues related to sourcing and...

The FTC requires jewelers to accurately represent the diamond quality grading systems they use. Learn the guidelines and protect yourself...

The Hanneman System makes evaluating diamond cuts easier. You can use total height and C/P ratios to cut grade round...

The Hanneman System simplifies cut diamond grade categories. Learn how to identify the worst cut stones quickly before taking unnecessary...

In the Hanneman cut grading system, you must consider diamond proportions to grade a round brilliant stone. Learn what they...

With the Hanneman diamond cut grading system, you can derive the cut grade of any round brilliant with minimal measurements...

Mastering the art of color grading white diamonds is a challenge. Learn about the standards, terms, tools, and testing procedures...

Can gem grading avoid subjective terms? Learn about gemologist Jeff Graham's common sense gemstone grading system, an alternative to commercial...

"Just Ask Jeff" shares his thoughts on the Color Stone Grading System of The GIA. In May 2008, he had...