Technical Articles
Lab Notes
- 2022-03-02: Star Sapphire Doublets (PDF File Size: 1 MB)
- 2021-10-07: Update on Purple Spinel from Afghanistan (PDF File Size: 462 KB)
- 2021-05-17: Pink Diaspore from Afghanistan (PDF File Size: 356 KB)
- 2021-01-20: A Rare Bicoloured Spinel (PDF File Size: 283 KB)
- 2020-09-29: Laurentthomasite, a New Gem Mineral (PDF File Size: 365 KB)
- 2020-09-18: RABBIT’S EYE RED AND GOLDEN RED. GIT’S NEW RUBY COLOR STANDARDS (PDF File Size: 275 KB)
- 2020-09-02: A RARE COLORLESS GARNET (PDF File Size: 474 KB)
- 2020-08-27: "BLUE JADE": A Rare Jadeite-Jade (PDF File Size: 810 KB)
- 2020-05-08: Zultanite Imitation (PDF File Size: 309 KB)
- 2020-04-08: Effect of Beryllium Heat Treatment in Synthetic Ruby
- 2020-03-06: BLUE RICHTERITE (PDF File Size: 439 KB)
- 2020-02-16: An Update on Mineral Inclusions and Their Composition in Ruby from the Bo Rai Gem Field in Trat Province, Eastern Thailand (PDF File Size: 1 MB)
- 2020-02-16: MINERAL INCLUSIONS IN RUBY AND SAPPHIRE FROM THE BO WELU GEM DEPOSIT IN CHANTHABURI, THAILAND (PDF File Size: 2 MB)
- 2019-10-26: Blue Diffusion-treated Natural & Synthetic Sapphires recently available in the Market (PDF File Size: 4 MB)
- 2019-10-25: Mineral inclusions in sapphire from the basalt-related deposit in Bo Phloi, Kanchanaburi, western Thailand: indication of their genesis (PDF File Size: 1.4 MB)
- 2019-09-30: Characteristics of Tairus Hydrothermally-Grown Synthetic Ruby and Blue Sapphire (PDF File Size: 5 MB)
- 2019-06-07: A Treated Mixed-Type Synthetic Yellow Diamond (PDF File Size: 3 MB)
- 2019-02-26: Squeezing Sapphire • Corundums treated with high temperatures and low pressure (HT+P)
- 2019-02-04: LMHC's presentation on "Sapphire Heated with Pressure" at Gemstone Industry & Laboratory Conference (GILC), Tucson on February 4th, 2019 (PDF File Size: 4 MB)
- 2019-01-15: Exceptional-Quality "MUSGRAVITE" (PDF File Size: 557 KB)
- 2018-11-29: LMHC Makes Progress On Harmonisation Of Colour Description And New Treatment Issues
- 2018-11-27: A Rare Nearly-Pure End-Member Grossular Garnet with Color-Change Effect (PDF File Size: 579 KB)
- 2018-09-18: Characteristics of Faceted-Quality Ruby from Longido, Tanzania (PDF File Size: 357 KB)
- 2018-09-04: Sri Lankan Sapphire Enhanced by Heat with Pressure (PDF File Size: 5.7 MB)
- 2018-08-20: New Blue-diffused Sapphires From Synthetic VS Natural Starting Maerials (PDF File Size: 4.39 MB)
- 2018-08-20: Characteristics of Commercial Grade Blue Sapphire Enhanced by Heat & Pressure (PDF File Size: 3.38 MB)
- 2018-04-19: RARE PINK POUDRETTEITE (PDF File Size: 291 KB)
- 2017-11-13: Rare Fancy Sapphires from Bo Phloi Gem Field, Kanchanaburi, (PDF File Size: 178 KB)
- 2017-11-13: Padparadscha Color Grading for Gem Trade (PDF File Size: 238 KB)
- 2017-11-13: Characteristics of exceptionally gem-quality untreated blue sapphires (PDF File Size: 147 KB)
- 2017-06-16: GIT 2016 Pre-Conference Field Trip to Mogok, Myanmar (PDF File Size: 2.86 MB)
- 2017-03-30: GEM-QUALITY GRANDIDIERITE FROM MADAGASCAR (PDF File Size: 899 KB)
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2017-02-21: CVD Synthetic Diamond Identifed
in the GIT-GTL (PDF File Size: 1.7 MB)
- 2016-11-29: Golden Sheen and Non-Sheen Sapphires from Kenya (PDF File Size: 3.23 MB)
- 2016-11-29: Identification and Stability of Cobalt Diffusion-Treated Spinel(PDF File Size: 6.18 MB)
- 2016-11-29: Burmese Sapphire from Mogok: its Inclusions and Country of Origin Determination(PDF File Size: 14 MB)
- 2016-11-29: Characteristics of Untreated Sapphire from Inverell, Eastern Australia: An Update (PDF File Size: 15 MB)
- 2016-11-29: A New "Purple Rhodolite" Garnet from Mozambique: Its Characteristics & Properties(PDF File Size: 80 MB)
- 2016-10-07: Phase Transformation of Epigenetic Iron Staining: Indication of Low-Temperature Heat Treatment in Mozambique Ruby (PDF File Size: 1.79 MB)
- 2016-09-28: SOME UNCOMMON FEATURES IN A HEAT-TREATED FANCY SAPPHIRE (PDF File Size: 774 KB)
- 2016-09-09: Cymrite: An Unusual Jade Imitation (PDF File Size: 298 KB)
- 2016-07-26: Blue Sapphire Undergone High Pressure High Temperature Enhancement (PDF File Size: 262 KB)
- 2016-07-15: A Lead-Glass-Filled Corundum Doublet (PDF File Size: 1.06 MB)
- 2016-05-11: Preliminary Investigation of Purple Garnet from a New Deposit in Mozambique (PDF File Size: 318 KB)
- 2016-03-01: Synthetic ruby filled in marble (PDF File Size: 435 KB)
- 2015-09-04: Synthetic ruby overgrowth on natural corundum (PDF File Size: 1.98 MB)
- 2015-09-04: Treated black sapphire (PDF File Size: 1.98 MB)
- 2015-07-16: Yellow Lead-Glass-Filled Sapphire (PDF File Size: 323 KB)
- 2015-05-26: Green Lead-Glass-Filled Sapphires (PDF File Size: 1 MB)
- 2015-03-13: GIT’S URGENT RELEASE on The new treatment of gem material marketed by the name of “Organic Ruby” (PDF File Size: 314 KB)
- 2015-03-03: SYNTHETIC RUBY OVERGROWTH ON NATURAL CORUNDUM (PDF File Size: 309 KB)
- 2014-10-22: Some Characteristics of Taaffeite from Myanmar (PDF File Size: 1.28 MB)
- 2014-07-23: "Ruby and Sapphire Grading Tools", InColor magazine, Spring2014 (PDF File Size: 395 KB)
- 2014-06-03: The Characteristics of amber from Indonesia (PDF File Size: 2.67 MB)
- 2014-01-17: A TREATED STONE SOLD AS ‘BLACK SAPPHIRE’ (PDF File Size: 746 KB)
- 2013-08-26: RECONSTRUCTED SAPPHIRE: A NEW TYPE OF MANMADE GEM CORUNDUM (PDF File Size: 447 KB)
- 2013-08-19: AN UNUSUAL PINK OPAL (PDF File Size: 317 KB)
- 2013-06-14: Cobalt-doped glass-filled sapphires: An update (PDF File Size: 2.52 MB)
- 2012: GIT LAB INFO FACT SHEET ON 'PARAIBA' TOURMALINE (PDF File Size: 176 KB)
- 2012: "The Artificial Blue Glass" Sold As Rare Gemstone "HAUYNE" (PDF File size: 320 KB)
- 2012: Blue Dyed and Clarity Modified Sapphire with Cobalt+Lead-glass filler in Fractures and Cavities (PDF File size: 456 KB)
- 2011: New Paraiba-type tourmaline from Mozambique (PDF File size: 562 KB)
- 2010: Natural Red Andesine from Tibet (PDF File Size: 3.58 MB)
- 2010: Unusual Cultured Pearls (PDF File Size: 1.12 MB)
- 2010: Flux grown synthetic Ruby with high iron content (PDF File Size: 2.20 MB)
- 2010: Provision of Full Disclosure Practices for Gem Trade (PDF File Size: 64 KB)
- 2010: New Ruby Deposits in Mozambique (PDF File size: 1.50 MB)
- 2010: An update on Titanium-diffused Sapphire (PDF File size: 2.19 MB)
- 2009: Some Characteristics of "Mozambique" Ruby (PDF File size: 2.62 MB)
LMHC Information
