Peridot
Found in lava, meteorites, and deep in the earth's mantle, yellow-green peridot is the extreme gem
OVERVIEW
ABOUT PERIDOT
The ancient Egyptians mined peridot on the Red Sea island of Zabargad, the source for many large fine peridots in the world’s museums. The Egyptians called it the “gem of the sun.” Today this gem is still prized for its restful yellowish green hues and long history. Large strongly-colored, examples can be spectacular, and attractive smaller gems are available for jewelry at all price points.
BIRTHSTONES & ANNIVERSARIES
Peridot is the birthstone for August and the 15th anniversary gemstone.
4.5 BILLION
Some peridot is ancient: it's found in pallasite meteorites, remnants of our solar system's birth.
STARDUST
In 2005, peridot was found in comet dust brought back from the
Stardust robotic space probe.
OLIVINE
Gem variety of the mineral olivine: found in peridotite rock from the
earth’s upper mantle.
FACTS
Mineral: Olivine
Chemistry: (MgFe)2SiO4
Color: Yellowish green
Refractive index: 1.65 to 1.69
Birefringence: 0.035 to 0.038
Specific gravity: 3.34
Mohs Hardness: 6.5 to 7
TREATMENTS
There are a number of processes used to alter the color, apparent clarity, or improve the durability of gems.
SYNTHETICS
Some gemstones have synthetic counterparts that have essentially the same chemical, physical, and optical properties, but are grown by man in a laboratory.
IMITATIONS
Any gem can be imitated—sometimes by manmade materials or by natural materials chosen by man to impersonate a particular gem.
WHY WE LOVE THIS GEMSTONE
1
Extraterrestrial
Peridot crystals are found in meteorites: some rare extraterrestrial crystals are even big enough to facet as cut gemstones.
2
Iron Gem
Most gems are colored by impurities such as iron. Peridot's color is intrinsically yellow-green. Higher-quality stones have an intense color.
3
Seeing Double
Peridot has extremely high double refraction: when you look closely through the gem, you can see two of each pavilion facet.
QUALITY FACTORS
Beautiful, yellowish green peridot has been treasured since earliest times.
COLOR
CLARITY
CUT
CARAT WEIGHT
PERIDOT QUALITY FACTORS: THE COMPREHENSIVE GUIDE
RESEARCH
Explore sources, gemological research, and the role of gems in history.
Nguyen Thi Minh Thuyet, Christoph Hauzenberger, Nguyen Ngoc Khoi, Cong Thi Diep, Chu Van Lam, Nguyen Thi Minh, Nguyen Hoang, and Tobias Häger , Nov 7, 2016
Andy H. Shen, John I. Koivula, and James E. Shigley , Nov 11, 2011
Ilaria Adamo, Rosangela Bocchio, Alessandro Pavese, and Loredana Prosperi , Jun 1, 2009
Robert E. Kane , Dec 1, 2004
RECOMMENDED READING
Gems of the World
Cally Oldershaw
Gems: Their Sources, Descriptions and Identification
Michael O'Donoghue
Gemstones: Symbols of Beauty and Power
Eduard Gubelin
