Rubies are no less popular today than they were in antiquity. In the colored gemstone industry and in the mind of the public, country of origin (or as some might suggest, “the fifth C”), is clearly a value factor in assessing stones. Ruby deposits are found across the globe. Sources include Afghanistan, Cambodia, East Africa, Thailand, and Vietnam. All deposits can yield fine-quality gem material, but certain locations have gained reputations as producers of exceptional stones. In particular, rubies from Burma are considered preeminent.
Burmese rubies are mined in a mountainous region, where most mining is of secondary alluvial deposits in the valleys amongst the peaks. The geology of the area is complex, consisting of high-grade schists and gneisses, granite intrusives and pegmatites, and ultramafic rocks. In addition, the terrain includes ruby and spinel-bearing marble, a type of metamorphic rock composed primarily of calcite. Rubies found in the alluvial deposits on valley floors have weathered out of these marble deposits. Rubies from metamorphic rocks such as marbles have a different trace element composition and a different set of inclusion minerals than rubies that have come from magmatic rocks. Metamorphic rubies tend to have very low iron content as compared to magmatic rubies. Metamorphic rubies are found in deposits around the globe, and so more subtle variations in trace element content can help distinguish metamorphic rubies from different locations.
In 1989 the country has been re-named Myanmar. Nevertheless, in deference to historical precedent, and as an acknowledgement of the gem’s peerless pedigree, connoisseurs still refer to the rubies from Mogok as “Burmese.” As is the case with many rural areas in Asia, men take care of the land (or the mining in the case of Mogok) while women take care of business. Keen-sighted and shrewed businesswomen dominate the ruby market in Mogok. Their love for the rubies passing through their hands is evident in their smiling eyes and softly toned voices as they calmly exhibit parcels that appear as if by magic. They handle the stones with such dexterity that gem trading is clearly a skill they developed early in their formative years.