Ruby is a red variety of the mineral corundum, an aluminum oxide known for its exceptional hardness and durability. Belonging to the oxide class and the hematite sub-class, rubies exhibit a vibrant red color due to the presence of chromium. The mineral forms in hexagonal crystal structures, with a range of transparency and crystal habits. The most desirable rubies are those with a deep, vivid red color and exceptional clarity.


The primary use of ruby is as a highly prized gemstone in the world of fine jewelry. Its striking red color, durability, and rarity make it a sought-after choice for engagement rings, necklaces, earrings, and other precious items. Rubies are also used in watchmaking, specifically for jewel bearings, due to their hardness and resistance to wear.


Ruby is considered one of the most valuable and prestigious gemstones, often commanding higher prices per carat than diamonds of similar quality. Its deep red hue symbolizes passion, love, and power, making it a popular choice for significant milestones and special occasions. The gemstone’s hardness and resistance to wear contribute to its enduring appeal, ensuring that a ruby can maintain its beauty and value for generations.


Rubies are formed in nature through a variety of geological processes, including metamorphism and the crystallization of high-temperature, aluminum-rich fluids. Chromium ions, responsible for ruby’s characteristic red color, replace aluminum ions in the corundum lattice during the crystal’s formation. This process can occur over various timescales, resulting in rubies of different sizes, colors, and crystal structures.


Rubies are found primarily in metamorphic rocks, such as marble and gneiss, as well as in igneous rocks like basalt. Some of the most significant deposits of ruby are found in countries such as Myanmar, Sri Lanka, Thailand, Afghanistan, and Madagascar. These regions are known for their favorable geological conditions that lead to the formation of this captivating red gemstone.


In metaphysical and spiritual practices, ruby is believed to have a range of properties. The gemstone is said to inspire courage, self-confidence, and passion, while also promoting emotional healing and balance. Ruby is considered a stone of protection and power, helping to ward off negative energies and enhance one’s determination and focus. Additionally, ruby is thought to stimulate the heart chakra, encouraging love, compassion, and devotion.

LusterAdamantine to vitreous
Hardness (Mohs)9
CleavageNone, but exhibits parting in one direction
Specific Gravity3.95 – 4.1