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Ruby
Ruby is the most valuable variety of the corundum mineral species, which also includes sapphire.
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Ruby with Interesting Synthetic Overgrowth
Microscopic examination of a ruby at the Carlsbad laboratory reveals synthetic overgrowth indicative of high-temperature heat treatment.
“Electromagnetic Wave” Inclusion in Mong Hsu Ruby
Fiber-optic illumination reveals an electromagnetic wave-like pattern of particles in a ruby from Myanmar.
Extremely Rare Hellandite Inclusion Found in a Mogok Ruby
A rare inclusion is reported in ruby from the Mogok mine for the first time.
A Canary in the Ruby Mine: Low-Temperature Heat Treatment Experiments on Burmese Ruby
Documents heating experiments conducted on Burmese rubies to find useful indicators of heat treatment at temperatures below 1200°C.
Update from Mozambique’s Ruby Mines
A field gemology team from GIA provides an update on the ruby mining operations around Montepuez.
Extraterrestrial-Like Inclusion in Mozambique Ruby
A 3.03 ct stone submitted to GIA’s Bangkok laboratory was identified as a ruby from Mozambique with no indication of heating.
A Quantitative Description of the Causes of Color in Corundum
Presents a quantitative means of determining the causes of color in a gem material, using corundum’s six major chromophores as an illustration.
Not All That Glitters is Gold — Sometimes it is Mozambican Rubies
Learn about Mozambican rubies, including their mining history, characteristics and market demand.
Geology of Corundum and Emerald Gem Deposits: A Review
Over the last two decades, knowledge of the formation of gem deposits has improved significantly. This article reviews the state of our knowledge of the geology and genesis of gem corundum and emerald deposits.
A Review of Analytical Methods Used in Geographic Origin Determination of Gemstones
Geographic origin determination relies on a combination of gemological observations and advanced analytical tools. This contribution reviews the analytical methods commonly used to establish origin.
The Geographic Origin Dilemma
An overview of the geographic origin complexities facing the gem and jewelry industry today.
Field Gemology: Building a Research Collection and Understanding the Development of Gem Deposits
With more than 90 field expeditions on six continents since 2008, GIA has accumulated over 22,000 colored stone reference samples. This extensive collection of colored stones with known origins supports GIA’s research on geographic origin determination.
