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.
Causes of Iridescence in Natural Quartz
Describes the occurrence of iridescence, and the role of differential etching, in quartz crystals from India’s Jalgaon District.
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.
Amethyst from Boudi, Morocco
An introduction to Moroccan amethyst, which features distinctive color zoning and inclusions.
The Wittelsbach Blue
This article describes what is known about the Wittelsbach Blue since it was first reported in 1666, and the gemmological information released to date on this diamond.
Gem-Quality Andalusite from Brazil
Widely known as a rock-forming mineral, andalusite is not frequently encountered as a gem material.
A Crystallographic Analysis of the Tavernier Blue Diamond
This study uses both historical information and modern data to create a computer model of the Tavernier Blue, orienting the finished diamond within the original diamond crystal.
Diopside Needles as Inclusions in Demantoid Garnet from Russia: A Raman Microspectrometric Study
Straight, acicular, colourless solid inclusions in demantoid garnet from the Ural Mountains of Russia were investigated by laser Raman microspectrometry.
Some Diagnostic Features of Russian Hydrothermal Synthetic Rubies and Sapphires
Most Russian hydrothermal synthetic rubies and pink, orange, green, blue and violet sapphires—coloured by chromium and/or nickel—reveal diagnostic zigzag or mosaic-like growth structures associated with colour zoning.
Barite Inclusions in Fluorite
Hemispherical aggregates of the mineral barite were identified as inclusions in fluorite from Illinois.