Article Search Results

Show Filters
Showing 135 results for "*"
A face-up view of a cushion cut diamond with blue color.
Article
Gems & Gemology’s 7 Most Unusual Encounters from 2019

Check out some of the most interesting and unusual diamonds and coloured stones submitted to GIA’s laboratories in 2019.

Read More

A row of various shaped cut and polished pink diamonds.
Article
Why are Pink Diamonds Pink? GIA Researchers Dive Deep into their Crystal Structure

GIA researchers analysed more than 90,000 natural pink diamonds to better understand how these rare and beautiful diamonds formed and got their colour.

Read More

The wax-impregnated bangle (left) showed bluish fluorescence under long-wave UV.
Strong Fluorescence in B-Jade Impregnated with Wax

A bangle is an example of the misconception that B jade is only impregnated by resin, when in fact wax-impregnated jadeite is also considered B-jade.

Read More

Two white jade bracelets with dark color patches.
Nephrite Bracelet with Filled Cavity

A jade bracelet contains unusual fillers, used to create a smooth surface.

Read More

These rubies were determined to be glass filled, partly due to the use of the DiamondView.
Separating Glass-Filled Rubies Using the DiamondView

The DiamondView instrument is able to identify glass as the filler in a pair of heart-shaped rubies.

Read More

HPHT-treated blue diamond (left) with ragged-looking graphitization around an inclusion (center) and high-order interference colors with crossed-polarizing filters (right).
Large HPHT-Treated Blue Type IIb Diamond

Properties of, and theories on colour zoning exhibited by, the largest HPHT-treated blue diamond graded by GIA.

Read More

This 20.60 ct specimen was purchased by the client as a “natural white pearl.”
Filled Pearl with Surface Features

A pearl, thought to be natural, is revealed to be a bead-cultured specimen with a pre-drilled nucleus.

Read More

These two opals were represented as natural-color blue and pink opal from Mexico.
Update on Dyed Hydrophane Opal

Opal purportedly from a new deposit is found to be dyed.

Read More

Top: The drilled green briolettes. Bottom: Fluid inclusions, crystals, and two-phase inclusions.
Coated Beryl Imitating Emerald

Coating on a beryl demonstrates the importance of thorough examination of jewellery and gem materials.

Read More

Micro-Features of Ruby
Inclusions in Natural, Synthetic and Treated Ruby

Provides a visual guide to the internal features of natural, synthetic and treated rubies.

Read More