Ruby
Ruby is an oxide mineral valued for its hardness and gem potential, with known Chinese sources.
About Rubyextended article
Red variety of corundum colored by Cr³⁺. Burmese Mogok material the historical reference.
Full mineralogical data
Ruby is a named variety, not a separate species. For complete data on chemistry, crystal system, hardness, optics, paragenesis, treatments, and inclusions — refer to the parent species:
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Identification & care
Crystals commonly develop as tabular to prismatic hexagonal crystals; barrel-shaped; massive. Its color is typically red. The luster is vitreous, adamantine, the streak is white, and specimens range from transparent to opaque. The cleavage is none — parting on {0001} and {1011}. The fracture is conchoidal, which aids identification.
Collector context
How it forms
In terms of geology, Ruby forms in metamorphic rocks (marble), alluvial deposits; also basaltic intrusions. It is commonly found in association with spinel, calcite, dolomite, graphite, phlogopite.
Classic Chinese localities
Ruby has known Chinese occurrences in Yunnan.
Why collectors care
Ruby occupies a rare position: it matters equally to specimen collectors and to the gem trade. Crisp natural crystals with saturated color and good clarity command premium pricing and are among the highest-prestige targets in any systematic collection.
What affects value
Value in Ruby is assessed, in typical order of weight, against: (1) locality provenance; (2) crystal size; (3) transparency and internal clarity; (4) color intensity and saturation; (5) crystal form and termination sharpness; (6) matrix and associated-species aesthetics; (7) gem-cutting potential. Verified locality documentation and cutting potential further elevate collector demand.
Naming history
The name Ruby has a specific etymological and historical context — see Mindat's reference entry for provenance details. We have retained naming data at the record level; published prose is paraphrased from factual fields rather than copied from source.