GIA COLORED STONES FINAL NOTES
QUESTIONS WITH 100% CORRECT
ANSWERS.
Corundum ANSWER : - Aluminium Oxide
Renowned Source Marble Metamorphic ANSWER : - Myanmar, Afghanistan, North vietnam
Metasomatic corundum sources ANSWER : - Mozambique, India, Kenya, Sri Lanka, Tanzania and central
Vietnam.
Metasoamtic ANSWER : - Metamorphic process in which minerals exchange their chemical components
in the presence of fluids
Desilicat ion ANSWER : - removes silicon from the rock
Mozapbique ruby rock ANSWER : - Aphibolite, metamorphic rock of amphibole.
Burmese rubies ANSWER : - create minute inclusions that create softness and fluoresce to LWUV and
SWUV
Thai Pailin Rubies ANSWER : - red have brownRed to purpleRed md to mdk, dont fluoresce
Crimson and scarlet ANSWER : - slp and sloR respectively
Habits of ruby ANSWER : - tabular hexagonal prism, some elongated prisms and bipyramids.
Ruby cutting ANSWER : - cut table perpendicular to table length
,Basalt heat for ruby ANSWER : - drops brown hue and removes blue zoning
1980 most quantity produced Ruby ANSWER : - Thailand and Cambodia. They heated them to 800-1250
in oxidizing environment to remove blue color. Also worked for Myanmar and Vietnam.
Flux healing ruby1 ANSWER : - 1250-1700 in presence of flux repaired fractures, people before that flux
only helped heat, but it also healed.
Lattice diffusion on dark ruby ANSWER : - can brighten cfkBr corundum to sloR.
Mozambique Ruby information ANSWER : - 2010, Montepuez, biggest ruby source. Gemfields made
MRM. Mined in riber channels, paleochannels. Are metasomatic. Associated with feldspar rich veins
intruding into amphibolite
Madagascar Ruby information ANSWER : - 1990. 2000 main source of sapph. Ruby deposit in
Vatomandry district. 20004 new source Andilamena and Moramanga. Most went to THailand to be lead
glass filled. Two more Madagascar deposits in Didy and Zahamena, Usually referred to as fire engine red
(sloR) also had color zoning.
Tanzania Ruby Information ANSWER : - First discovered in Longido 1900. Most of the production is
carving quality, consisting of hexagonal crystals, enclosed in a dark rock of green zoisite and g-b
amphibole. small percentage is facet grade. Umba river valley, also has rubies. 2007, fine quality pure
red to slpR found in Winza village. Had awesome TP and had vB color zones. Didnt need heat. 5000
independent miners worked the area. 2009 it was diminished.
Melawi Ruby Information ANSWER : - Chimwadzulu hill, facet and fine quality. 1958, similar to
amphibole, mica and feldspar bearing areas. Nyala mine, established 2008, with Columbia Gem house.
2013 Malawian national bought 80% mining operation. 20% owned by government.
Myanmar Ruby Information ANSWER : - Myanmar: Mogok and Mong Hsu. Mogok mining is 2150m
above. Covers 175km squared. 90% ruby, 10% sapphire. Marble hosted, landscape filled with marble
pinnacles called karsts. Weathering processes that formed them blackened their surfaces and also
transported marble and ruby into gem gravels called byon. Alluvial, eluvial and hard rock operations.
They use jigs to seperate minerals and corundum.
, Vietnam Ruby Information ANSWER : - 1980, Luc Yen district, Tan Huong, Quy Chau. Range of tones and
saturations. Terrain of Luc Yen, similar to Mogok environment, which have karsts. Harder to hike
through. Vietnam National Gem and Gold Corp, created by Government. Joint venture with Thai
company, they started mining and send to THailand. 1994 It ended, smaller scale mining operations took
over. 1990, thousands of miners went to Quy Chau, Government shut it down. Tan Huong, produced
mid 1990, had star rubies.
Central Asia Ruby Information ANSWER : - Tajiksistan, Afghanistan and PAkistan. Tajikistan, 4000m up.
found 1970, produced 1980, but had conflicts. Today the production is confidential. Afghanistan,
produced over 700 years. Jegdalek. Mining in deep trenches. usually makes cabochons. Pakistan,
Batakundi, Hunza Valley and Nangimali. Nangimali is tunnel on side of marble cliffs, 4000m in the air.
small but good color. Hunza valley usually cabochons. These can all be found in Peshawar market. Also
found in Mepal.
Ruby Synthetic Information ANSWER : - First man made gem material was synthetic ruby. 1995,
introduced, named Geneva ruby as they said it was found in Geneva. False. 1904, Verneuil, made ruby
with melt process, or flame fusion. Ruby made from both melt and solution. Melt is cheap. Pulling or
Czochralski is used to make ruby for tech. It makes synthetic ruby lasers work. Melt process, found in
commercial jewelry. It can take hours or days to make flame fusion ruby. But flame fusion also seems
more like natural. products are so distinctive, people call them Chatham, Kashan and Ramaura flux and
Tairus/Russiand hydrothermal.
Sapphire Compliment ANSWER : - Sapphire complements platinum or white gold mountings.
China Biggest Market ANSWER : - China biggest market of platinum, strong market for sapphire.
Source of Basalt for Sapph ANSWER : - Regions of basalt are Cambodia, Thailand, Australia, China,
Nigeria, vietnam.
Source of non Basalt for Sapph ANSWER : - Sources are myanmar, Kashmir, Sri Lanka and mAdagascar.
Yogo Gulch, Montana, the sapphires are xenocrysts, brought to surface by rocks unrelated to formation
process. Carriers are basalt and a rare type of igenous rock called lamprophyre.
Metamorphism for Sapphires ANSWER : - Metamorphism contributes to sapphire formation in Sri
Lanka, and contact metamorphism for Mogok. Contact met. happens when magma intrudes into
surrounding rock and alterns it.
QUESTIONS WITH 100% CORRECT
ANSWERS.
Corundum ANSWER : - Aluminium Oxide
Renowned Source Marble Metamorphic ANSWER : - Myanmar, Afghanistan, North vietnam
Metasomatic corundum sources ANSWER : - Mozambique, India, Kenya, Sri Lanka, Tanzania and central
Vietnam.
Metasoamtic ANSWER : - Metamorphic process in which minerals exchange their chemical components
in the presence of fluids
Desilicat ion ANSWER : - removes silicon from the rock
Mozapbique ruby rock ANSWER : - Aphibolite, metamorphic rock of amphibole.
Burmese rubies ANSWER : - create minute inclusions that create softness and fluoresce to LWUV and
SWUV
Thai Pailin Rubies ANSWER : - red have brownRed to purpleRed md to mdk, dont fluoresce
Crimson and scarlet ANSWER : - slp and sloR respectively
Habits of ruby ANSWER : - tabular hexagonal prism, some elongated prisms and bipyramids.
Ruby cutting ANSWER : - cut table perpendicular to table length
,Basalt heat for ruby ANSWER : - drops brown hue and removes blue zoning
1980 most quantity produced Ruby ANSWER : - Thailand and Cambodia. They heated them to 800-1250
in oxidizing environment to remove blue color. Also worked for Myanmar and Vietnam.
Flux healing ruby1 ANSWER : - 1250-1700 in presence of flux repaired fractures, people before that flux
only helped heat, but it also healed.
Lattice diffusion on dark ruby ANSWER : - can brighten cfkBr corundum to sloR.
Mozambique Ruby information ANSWER : - 2010, Montepuez, biggest ruby source. Gemfields made
MRM. Mined in riber channels, paleochannels. Are metasomatic. Associated with feldspar rich veins
intruding into amphibolite
Madagascar Ruby information ANSWER : - 1990. 2000 main source of sapph. Ruby deposit in
Vatomandry district. 20004 new source Andilamena and Moramanga. Most went to THailand to be lead
glass filled. Two more Madagascar deposits in Didy and Zahamena, Usually referred to as fire engine red
(sloR) also had color zoning.
Tanzania Ruby Information ANSWER : - First discovered in Longido 1900. Most of the production is
carving quality, consisting of hexagonal crystals, enclosed in a dark rock of green zoisite and g-b
amphibole. small percentage is facet grade. Umba river valley, also has rubies. 2007, fine quality pure
red to slpR found in Winza village. Had awesome TP and had vB color zones. Didnt need heat. 5000
independent miners worked the area. 2009 it was diminished.
Melawi Ruby Information ANSWER : - Chimwadzulu hill, facet and fine quality. 1958, similar to
amphibole, mica and feldspar bearing areas. Nyala mine, established 2008, with Columbia Gem house.
2013 Malawian national bought 80% mining operation. 20% owned by government.
Myanmar Ruby Information ANSWER : - Myanmar: Mogok and Mong Hsu. Mogok mining is 2150m
above. Covers 175km squared. 90% ruby, 10% sapphire. Marble hosted, landscape filled with marble
pinnacles called karsts. Weathering processes that formed them blackened their surfaces and also
transported marble and ruby into gem gravels called byon. Alluvial, eluvial and hard rock operations.
They use jigs to seperate minerals and corundum.
, Vietnam Ruby Information ANSWER : - 1980, Luc Yen district, Tan Huong, Quy Chau. Range of tones and
saturations. Terrain of Luc Yen, similar to Mogok environment, which have karsts. Harder to hike
through. Vietnam National Gem and Gold Corp, created by Government. Joint venture with Thai
company, they started mining and send to THailand. 1994 It ended, smaller scale mining operations took
over. 1990, thousands of miners went to Quy Chau, Government shut it down. Tan Huong, produced
mid 1990, had star rubies.
Central Asia Ruby Information ANSWER : - Tajiksistan, Afghanistan and PAkistan. Tajikistan, 4000m up.
found 1970, produced 1980, but had conflicts. Today the production is confidential. Afghanistan,
produced over 700 years. Jegdalek. Mining in deep trenches. usually makes cabochons. Pakistan,
Batakundi, Hunza Valley and Nangimali. Nangimali is tunnel on side of marble cliffs, 4000m in the air.
small but good color. Hunza valley usually cabochons. These can all be found in Peshawar market. Also
found in Mepal.
Ruby Synthetic Information ANSWER : - First man made gem material was synthetic ruby. 1995,
introduced, named Geneva ruby as they said it was found in Geneva. False. 1904, Verneuil, made ruby
with melt process, or flame fusion. Ruby made from both melt and solution. Melt is cheap. Pulling or
Czochralski is used to make ruby for tech. It makes synthetic ruby lasers work. Melt process, found in
commercial jewelry. It can take hours or days to make flame fusion ruby. But flame fusion also seems
more like natural. products are so distinctive, people call them Chatham, Kashan and Ramaura flux and
Tairus/Russiand hydrothermal.
Sapphire Compliment ANSWER : - Sapphire complements platinum or white gold mountings.
China Biggest Market ANSWER : - China biggest market of platinum, strong market for sapphire.
Source of Basalt for Sapph ANSWER : - Regions of basalt are Cambodia, Thailand, Australia, China,
Nigeria, vietnam.
Source of non Basalt for Sapph ANSWER : - Sources are myanmar, Kashmir, Sri Lanka and mAdagascar.
Yogo Gulch, Montana, the sapphires are xenocrysts, brought to surface by rocks unrelated to formation
process. Carriers are basalt and a rare type of igenous rock called lamprophyre.
Metamorphism for Sapphires ANSWER : - Metamorphism contributes to sapphire formation in Sri
Lanka, and contact metamorphism for Mogok. Contact met. happens when magma intrudes into
surrounding rock and alterns it.
