YOUR SOURCE FOR COLOR

Ruby is the red variety of the mineral corundum, a crystalline form of aluminum oxide (Al₂O₃). In its pure form corundum is colorless, but trace amounts of chromium substituting for aluminum in the crystal lattice produce ruby’s signature red color, with more chromium generally resulting in stronger red saturation. Rubies crystallize in the trigonal system and are exceptionally **hard—rating 9 on the Mohs scale of mineral hardness—**second only to diamond among natural gems. This high hardness, combined with excellent toughness and lack of cleavage, makes ruby especially suitable for everyday jewelry like rings and bracelets.

In gemology, color is the most critical quality factor for ruby: the finest stones exhibit a pure, vibrant red to slightly purplish red, often referred to in trade as “pigeon’s blood.” Other factors such as clarity, cut, and carat weight also influence value, but because many rubies contain growth features or inclusions, experienced gemologists use laboratory testing to distinguish natural from synthetic or treated stones. Historically prized across cultures and still highly esteemed today, ruby remains one of the most iconic and coveted colored gemstones.