Identification of “Pistachio” Coloured Pearls Treated by Ballerina Pearl Co.
A report on the colour treatment process for these intensely greenish yellow to yellowish-green cultured pearls and the techniques for identifying them.
Variscite from Central Tajikistan: Preliminary Results
A look at the gemmological properties and chemical composition of this light blue to light green to green gem material, which is suitable for cabochon cutting.
The Very Deep Origin of the World’s Biggest Diamonds
Explores an exceptional family of diamonds, referred to as “CLIPPIR” (Cullinan-like, Large, Inclusion-Poor, Pure, Irregular and Resorbed), that formed in a super-deep environment.
True Colours of “Dalmatian Jasper”
Discusses the mineralogical composition and provenance of this spotted decorative gemstone.
Synthetic Star Sapphires and Rubies Produced by Wiede’s Carbidwerk, Freyung, Germany
Details the process used by Wiede’s Carbidwerk to produce star synthetic corundum from the mid-1950s until the 1970s.
Photoluminescence Spectra of Emeralds from Colombia, Afghanistan and Zambia
Compares PL spectroscopy data of 48 emerald samples from three countries to evaluate the usefulness of the technique in geographic origin determination.
Characterisation of Mg and Fe Contents in Nephrite Using Raman Spectroscopy
Evaluates the usefulness of Raman spectroscopy in distinguishing the colour varieties of nephrite based on the relative ratio of Mg to Fe concentration.
Japanese Jadeite: History, Characteristics and Comparison with Other Sources
Examines the sources, colour, texture and chemical composition of jadeite from Japanese deposits.
Cuprian Liddicoatite Tourmaline
Identifies 13 copper-bearing tourmalines, which have traditionally been assumed to be elbaite species, as liddicoatite.
Chrysoberyl from the New England Placer Deposits, New South Wales, Australia
Examines a collection of chrysoberyl samples from these sapphire placer deposits to determine their distinct mineralogical and chemical properties.