Natural Color-Change Alexandrite Guide: History and Information

Article by Sumeet Chordia, G.G.

A Natural and Certified Brazil Alexandrite. © RAF Jewels

Alexandrite is a variety of Chrysoberyl, a mineral that is chemically Beryllium Aluminate (BeAl2O4). The gemstone is most notable for its distinct color-change effect – a shift between a green-blue to a purple-red hue under daylight and incandescent light, respectively. The gem was serendipitously discovered when miners extracted emeralds from sites within Russia's Ural Mountain Range between 1829 and 1833. From excavating hundreds of emerald specimens, they recovered only one of these types of color-changing mineral.

Upon its discovery, authorities controlling the mine sent samples to the country's mineralogical department for further study and analysis. Mineralogists studied the gemstone carefully and published numerous accounts of its properties and unique phenomena. They confirmed it as a variety of cymophane, another name for Chrysoberyl. In 1834, the Russian Imperial Mineralogical Society recognized the gemstone's "first-rank" properties and changed its name to Alexandrite in honor of Tsarevich Alexander Nikolaevich (Tsar Alexander II) - the next Tsar of Russia.

While the gemstone mesmerized miners and geologists for its color-change phenomena, it also proved highly durable and resistant – the gem had no cleavage planes and registered 8.5 on the Mohs Hardness Scale[1]. For perspective, diamonds are 10, rubies and sapphires are 9, and emeralds are 7.5 - 8.

Remarkably, a recent analysis of Alexandrites by SSEF in Basel, Switzerland, uncovered the mystery behind its natural color-changing phenomena. Researchers at SSEF discovered that the color-change in Alexandrites occurs due to Chromium, a trace element, inside the mineral. When two distinct light sources, daylight and incandescent) carrying different spectrum emissions, illuminate the crystal its absorbs different color wavelengths and emits a different color. Notably, the absorption spectrum of Alexandrite was similar to those of emeralds and rubies.

Gemstone Origins: Series I: Introduction

Article by Sumeet Chordia, G.G.

If you have seen a description or a gemological report of a color gemstone, such as an Emerald, Ruby, Sapphire, Tourmaline, Alexandrite, etc. which states the name of a country then you have come across an important and highly valuable piece of information — that of gemstone origin. This is not to be confused with an origin for an article of jewelry, such as “Made In …” which is often stamped with the name of the manufacturing country or its distinct hallmarks.

In this first education series, we share basic information about the history, scientific methods, famous origins, risks, and value associated with the geographic origins of gemstones so you can gain a better understanding of the subject and make an informed decision about the purchase of an important gemstone or jewelry piece.

A gemstone’s geographic origin is the country, state, or region, from where the stone is believed to have been unearthed. It does not mean the location where it was cut, polished, traded, or set in a piece of jewelry.

It’s worth noting that the geographic origin of gemstones directly impacts its value. Whether it should is a healthy discussion and one that has been going on in the industry for decades. However, for the scope of this series, we will adhere to current market trends and demands.

Before we go further it is important to understand the impact and significance of gemstone origin. As an example, a ruby from one country can be sold for hundreds of dollars-per-carat and another ruby from a different country can be sold for hundreds of thousands to millions of dollars-per-carat. This raises significant responsibilities throughout the supply and value chain, especially before it reaches the hand of the end customers who rely on absolute trust from their jeweler.

While the variation in price may come as a surprise to many we hope our educational series sheds valuable information on this topic and helps address any questions or concerns. Our goal is to build an educated community so your experience with a gemstone or jewelry purchase is thoughtful, positive, and with minimal risk.

In order to move forward, we must take a step back and dive into history and visit the 1950s in the serene town of Lucerne, Switzerland where the idea and scientific study of geographic gemstone origin was introduced and established.

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