Spring Into a Colorful Week of GIA Virtual Events
CARLSBAD, Calif. – Jan. 21, 2021 – Register for GIA’s Knowledge Rocks Week: Spring Into Color for four days of exciting virtual events taking you deep into the beautiful world of colored stones.
Raman and photoluminescence mapping of gem materials
Eaton-Magaña S., Breeding C.M., Palke A.C., Homkrajae A., Sun Z.Y., McElhenny G. (2021) Raman and photoluminescence mapping of gem materials. Minerals, Vol. 11, No. 2, Art. 177.
The new mineral crowningshieldite: A high-temperature NiS polymorph found in a type IIa diamond from the Letseng mine, Lesotho.
Smith E.M., Nestola F., Pasqualetto L., Zorzi F., Seccon L., Wang W. (2021) The new mineral crowningshieldite: A high-temperature NiS polymorph found in a type IIa diamond from the Letseng mine, Lesotho. American Mineralogist, Vol. 106, No. 2, pp. 301-309.
Heavy iron in large gem diamonds traces deep subduction of serpentinized ocean floor
Smith E.M., Ni P., Shirey S.B., Richardson S.H., Wang W., Shahar A. (2021) Heavy iron in large gem diamonds traces deep subduction of serpentinized ocean floor. Science Advances, Vol. 7, eabe 9773
Historical Reading List: Lazurite (Lapis Lazuli) from Afghanistan and its Artistic Use as a Blue Pigment (Ultramarine)
Annotated reading lists compiled on Lazurite (Lapis Lazuli) from Afghanistan and its Artistic Use as a Blue Pigment (Ultramarine)
Nitrogen in diamond
Ashfold M.N.R., Goss J.P., Green B.L., May P.W., Newton M.E., Peaker C.V. (2020) Nitrogen in diamond. Chemical Reviews, Vol. 120, No. 12, pp. 5745-6794.
Naturally colored yellow and orange gem diamonds: The nitrogen factor
Breeding C.M., Eaton-Magaña S., Shigley J.E. (2020) Naturally colored yellow and orange gem diamonds: The nitrogen factor. Gems & Gemology, Vol. 56, No. 2, pp. 194-219.
Decoration of growth sector boundaries with nitrogen vacancy centers in as-grown single-crystal high-pressure high-temperature synthetic diamond
Diggle P.L., D’Haenens-Johansson U.F.S., Green B.L., Welbourn C.M., Thi T.N.T., Katrusha A., Wang W., Newton M.E. (2020) Decoration of growth sector boundaries with nitrogen vacancy centers in as-grown single-crystal high-pressure high-temperature synthetic diamond. Physical Review Materials. Vol. 4, No. 9, Article 093402.
A quantitative description of the causes of color in corundum
Dubinsky E.V., Stone-Sundberg J., Emmett J.L. (2020) A quantitative description of the causes of color in corundum. Gems & Gemology, Vol. 56, No. 1, pp. 2-28.
Comparison of gemological and spectroscopic features in type IIa and Ia natural pink diamonds
Eaton-Magaña S., McElhenny G., Breeding C.M., Ardon T. (2020) Comparison of gemological and spectroscopic features in type IIa and Ia natural pink diamonds. Diamond and Related Materials, Vol. 105, Article 107784.
Spatial distribution of defects in natural type IIb diamond after irradiation and annealing
Eaton-Magaña S., Ardon T. (2020) Spatial distribution of defects in natural type IIb diamond after irradiation and annealing. Diamond and Related Materials. Vol. 109, Article 108034.
Natural color D-to-Z diamonds: A crystal clear perspective
Eaton-Magaña S., Ardon T., Breeding C.M., Shigley J.E. (2020) Natural color D-to-Z diamonds: A crystal clear perspective. Gems & Gemology, Vol. 56, No. 3, pp. 318-335.
Yellow and Orange Diamonds, New Identification Techniques, and the Chronicles of Chivor
An overview of the Summer 2020 Gems & Gemology content.
Böhmite in Corundum
Rubies from Mozambique, which were examined at the Lotus Gemology lab in Bangkok, proved to be infilled with böhmite, a secondary mineral in corundum.
Fluorophlogopite in Burmese Spinel
Lotus Gemology in Bangkok received a large parcel of dark red spinels for identification.
A Sapphire with a Negative Crystal Containing a Mobile Graphite Daughter Crystal
Mineral and fluid phases within negative crystals in metamorphic sapphires provide us with general information on the sapphire and the trapped fluid itself.
Windmills in Rare Mineral Sphalerite
Whimsical windmill-like inclusions are found in a high-quality orange specimen of the rare mineral sphalerite.
Separation of Natural from Laboratory-Grown Diamond Using Time-Gated Luminescence Imaging
Researchers from De Beers Group Technology present a technique that expands on the surface luminescence used in the DiamondView instrument to provide additional imaging information and quickly distinguish colorless or near-colorless natural diamond from laboratory-grown diamond.
Optical Whitening and Brightening of Pearls: A Fluorescence Spectroscopy Study
Presents a study that suggests optically brightened pearls can be consistently separated from non-brightened pearls using fluorescence spectroscopy.