Cuprian (copper-bearing) tourmaline, known as “Paraíba” tourmaline in the trade, has been an important gem since its discovery in 1989. Until now, almost all of the material reported has been ...
Investigates the morphological changes of macle diamonds during the growth process by exploring their three-dimensional internal zonal structure.
A chemical and spectroscopic comparison of two purple gem spinel samples, one of them the first reported example of a spinel with a saturated purple color caused predominantly by chromium and cobalt.
Earth’s surface is divided into tectonic plates, and the ones that make up the ocean floor are destined to sink. Sheets of oceanic crust typically bend and sink down into Earth’s interior at so-called ...
An Identification Report, with geographic origin added. For polished, loose or mounted natural alexandrite, demantoid, emerald, jade, opal, Paraíba tourmaline ...
When the same gems and precious metals are used in jewelry, design is the element that ultimately distinguishes one piece from another. Real success is measured not only by the value of its materials ...
Yusuke Katsurada, Ziyin Sun, Christopher M. Breeding, and Barbara L. Dutrow ...
Emerald is 7.5 to 8 on the Mohs scale and has fair to good toughness, making it a stone that requires more care in wearing than ruby or sapphire. Even so, emeralds are beautiful stones for all types ...
Common substances like sand and dust are composed mostly of quartz, the mineral species that includes the variety citrine. So, while citrine is a great gemstone for use in jewelry, it should be ...
Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or difficulty with which one mineral can be scratched by another. But the Mohs scale is deceptive.
Corundum is stable under normal wearing conditions, which means it’s resistant to the effects of heat, light, and common chemicals. Boric acid powder will etch the surface of even untreated stones.
Explore the world of diamonds and colored gemstones.
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