Research Article Search Results
Geographic Origin Determination of Alexandrite
The geographic source of this rare color-change gem has a significant impact on value. Trace element chemistry profiles allow GIA to accurately determine origin for alexandrite from several countries.
The Geographic Origin Dilemma
An overview of the geographic origin complexities facing the gem and jewelry industry today.
Geographic Origin Determination of Ruby
The world ruby market has undergone dramatic change in recent years, especially with the development of ruby mining in Mozambique. This contribution outlines GIA’s methods and criteria for establishing the geographic origin of ruby.
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.
Geographic Origin Determination of Paraíba Tourmaline
Copper-bearing gem tourmaline, known as Paraíba tourmaline after the location of its original discovery, is prized for its vivid blue to green color. This article explains GIA’s use of quantitative chemical analyses to distinguish samples from Brazil, Nigeria, and Mozambique.
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.
Geographic Origin Determination of Emerald
The relative chemical diversity of emeralds from different deposits worldwide allows clear origin determination in most cases. This contribution explains the criteria used by GIA to make geographic origin conclusions for emeralds.
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.
Faceted Diamond Octahedron with a Remarkable Stellate Cloud Inclusion
A remarkable inclusion scene in diamond is showcased by an unconventional cutting style.
Resin Imitation Ivory with a Pseudo “Engine-Turned” Structure
Resin materials marketed as imitation ivory were recently acquired by a GIA gemologist.
Laboratory-Grown Sapphire with Unusual Features
The Hong Kong laboratory recently examined a 14.36 ct pink-orange cushion mixed-cut specimen.
Possible Natural Abalone Shell Blister
An intriguing item was sent by KC Bell to GIA’s Carlsbad laboratory for examination.
