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

Annotated reading lists compiled on Lazurite (Lapis Lazuli) from Afghanistan and its Artistic Use as a Blue Pigment (Ultramarine)

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.

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.

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.

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.

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.

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.

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.

An overview of the Summer 2020 Gems & Gemology content.

Rubies from Mozambique, which were examined at the Lotus Gemology lab in Bangkok, proved to be infilled with böhmite, a secondary mineral in corundum.

Lotus Gemology in Bangkok received a large parcel of dark red spinels for identification.

Mineral and fluid phases within negative crystals in metamorphic sapphires provide us with general information on the sapphire and the trapped fluid itself.

Whimsical windmill-like inclusions are found in a high-quality orange specimen of the rare mineral sphalerite.

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.

Presents a study that suggests optically brightened pearls can be consistently separated from non-brightened pearls using fluorescence spectroscopy.

Presents the four major groups of defects responsible for the color in nearly all yellow and orange diamonds.

Many legends are told about the history of the Chivor emerald mine.

Raman spectroscopy confirms sea-blue beads with a similar appearance to Larimar are actually quench-crackled chalcedony.

A rough diamond crystal weighing 4.05 ct was observed with radiation staining on its surface.