Ammolite is often fashioned into pendants, brooches, and earrings, and sometimes sold as objet d’art. It is not a hard stone, 3.5 on the Mohs scale, which means it can scratch easily. Heat and ...

These environmental stresses create a unique "fingerprint" within each natural diamond that is only visible under deep-UV light. Much like the growth rings of a tree, these patterns tell a story of ...

Previously we introduced sapphire as a gemstone and as a major industrial material that spurred the advancement of many synthetic crystal growth techniques. Synthetic sapphire is commonplace in our ...

Another way to measure a ring is to take a measurement of the inside and determine the finger size from a standard chart. The inside of the ring must be perfectly round for this to work.

Natural mint-green chrysoberyl, much of it extremely clean, is also found in Ilakaka, Madagascar; Sri Lanka; and Mogok, Myanmar. Prior to this study, there had been very little investigation into ...

Within a short time, 90 more claims appeared in the same 20-square-mile area. No one was quite sure what the beautiful crystals were, but everyone wanted to lay claim to the profits they were certain ...

Zircon is rated 6 to 7.5 on the Mohs scale. It has fair to good toughness. While zircon is not as hard or tough as a stone like sapphire, it can still be worn in all types of jewelry as long as proper ...

GIA invented the science of grading diamonds with the 4Cs and the International Diamond Grading System ™ – standards used by jewelry professional around the world. So there’s no better place to study ...

Explore opal history, research, quality factors, and more in the GIA Gem Encyclopedia.

Explore topaz history, research, quality factors, and more in the GIA Gem Encyclopedia.

The phrase “light performance” gets a lot of loose use in the diamond trade. Terms such as brightness, brilliance, fire and scintillation are defined by various organizations with both clear and vague ...

Your name or store info is removed so grading is completely unbiased. Every pearl or pearl strand, whether from a local jeweler or a globally recognized brand, is evaluated using the same rigorous, ...