Alexandrite Gemstone | Natural Alexandrite Stone - GIA
Often described by gem aficionados as “emerald by day, ruby by night,” alexandrite is the very rare color-change variety of the mineral chrysoberyl. Originally discovered in Russia’s Ural …
Alexandrite Gemstone | Natural Alexandrite Stone - GIA
Alexandrite Gemstone is a rare variety of the mineral Chrysoberyl & is a strongly pleochroic gem. Color-changing alexandrite is nature’s magic trick.
Alexandrite Description - GIA
Alexandrite, with its chameleon-like qualities, is a rare variety of the mineral chrysoberyl. Its color can be a lovely green in daylight or fluorescent light, changing to brownish or purplish red in …
Alexandrite History and Lore - GIA
Discover the meaning and history of alexandrite, a June birthstone, and where it can be found.
Geographic Origin Determination of Alexandrite
2020年1月31日 · When an alexandrite first arrives at the GIA laboratory, we ask a question even more fundamental than geographic origin: Is this a natural alexandrite? Fourier-transform …
Alexandrite Quality Factors - GIA
Fine alexandrite is green to bluish green in daylight and red to purplish red in incandescent light. Its color saturation is moderately strong to strong. Stones that are too light do not reach the …
GIA Gem Encyclopedia | Complete List Of Gemstones
GIA’s Gem Encyclopedia is a virtual journey through the science and lore of gemstones from across the globe. Each precious stone page features additional detailed gemological …
Classification of Gem Materials Using Machine Learning
This study examines the application of several machine learning models to gemstone classification problems involving natural alexandrite, laboratory-grown diamonds, and natural …
Pleochroism and Color Change in Faceted Alexandrite: Influence of …
2015年7月31日 · Alexandrite, the chromium-bearing variety of chrysoberyl, shows distinct pleochroism and a signature color change between daylight (or daylight-equivalent fluorescent …
Alexandrite Care and Cleaning Guide - GIA
Learn about alexandrite's durability and how to care for your alexandrite jewelry.