GIA does not publish prices, or determine value, on gems or jewelry. There are several companies who publish pricing guides to which you may be able to subscribe. To remain neutral, GIA does not ...

Stability Alexandrite is stable under normal wearing conditions, which means it’s resistant to the effects of heat, light, and common chemicals. Cleaning Warm, soapy water is always safe for cleaning ...

Stability Amber burns at relatively low temperatures. With prolonged exposure to light it might darken, and it can be damaged by chemicals. Cleaning The only safe way to clean amber is with warm, ...

You can send your diamond to GIA for grading and analysis. Many consumers send the diamond through a retailer for packaging, shipping and insuring the item. A jeweler will have to remove your diamond ...

A synthetic gem material is one that is made in a laboratory, but which shares virtually all chemical, optical, and physical characteristics of its natural mineral counterpart, though in some cases, ...

Blue diffusion-treated sapphires are becoming more prevalent than ever before. The diffusion technique, which involves the addition of color-causing chemicals during heat treatment, results in a thin ...

To submit any item to GIA for analysis and grading services, you will need to submit a completed Client Agreement with your first shipment.

Heat treatment usually gives it a more bluish appearance. Aquamarine crystals are known to be large in size and relatively clean and well-formed, making them particularly valuable to collectors of ...

Transparent, bicolored quartz with the colors of both amethyst and citrine in the same gem is called ametrine or amethyst-citrine.

The gem was named after the young Alexander II, heir apparent to the throne. It caught the country’s attention because its red and green colors mirrored the Imperial Russian flag.

Figure 1. Pleochroism in a 15 ct tanzanite, as seen with the unaided eye through the crown and the pavilion sides and ends. Photo by Wimon Manorotkul. ABSTRACT While virtually all gemological texts ...

Gems & Gemology is the quarterly scientific journal of the Gemological Institute of America.