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Corundum Mineral | A-Z About This Mineral That You Need to Know

limz Published On Sun Apr 05 2020   Modified On Sun Apr 05 2020
Corundum Mineral | A-Z About This Mineral That You Need to Know

Corundum is a rock-forming mineral and is the second hardest mineral after Diamond and Moissanite. It belongs to the Hematite group of minerals and exhibits a trigonal crystal system. It is best known throughout the world as the mineral of Ruby and Sapphire and also for its hardness.

Corundum symbolizes hope, faith, strength, endurance, kindness, good health, and innocence.

Let us learn more about Corundum.


Corundum is a naturally occurring aluminum oxide mineral that is most commonly found as opaque crystals with dull colors. It is an extremely hard mineral and has two primary gem varieties: ruby and sapphire. 

These stones help to open up and balance the third-eye, throat, and heart. It helps to promote insight into the unknown, improve your verbal communication skills, and enhance our emotional development.

Origin and History

Corundum Mineral Specimen.
Corundum Mineral Specimen.
Image Source: Dakota Matrix Minerals

In 1725, Corundum was originally named "corinvindum" by John Woodward, an English geologist from the Sanskrit "kuruvinda" which means "Ruby". Later in 1794, an Irish chemist and geologist, Richard Kirwan changed the name into Corundum. 

For almost two centuries, these stones have been widely used throughout the world for industrial and manufacturing purposes. Throughout history, it has been known by many names such as adamant, sapphire, ruby, hyacinthos, asteria, etc.

Formation Process

Corundum is commonly found in carbonate, igneous, metamorphic, and sedimentary rocks. In igneous rocks, it is found as a primary mineral such as syenite, nepheline syenite, and pegmatite. Some of the notable places where fine specimen of these minerals are found are Zimbabwe, Pakistan, Afghanistan, Russia, Sri Lanka, USA, and India.


Crystal Structure of Corundum.
Crystal Structure of Corundum.
Image Source:

The chemical formula of Corundum is Al2O3 (Aluminium Oxide). It has a hardness of 9 on the Mohs scale.


  • Emery
  • Padparadscha
  • Sapphire
  • Star Sapphire
  • Ruby
  • Star Ruby
  • Ultralite

Colors Available

  • Colorless
  • Blue
  • Red
  • Pink
  • Yellow
  • Grey
  • Golden-Brown

Mines Available

  • Agua Rica Mine, Catamarca Province, Argentina
  • Mistral Ruby Mine, Northern Territory, Australia
  • Hills of Precious Stones Mine, Pailin Province, Cambodia
  • Deer Park Mine, British Columbia, Canada

Cost Per Carat

The value of Corundum can range anywhere from $10 to $100 according to its cut, color, clarity, and quality.


  • Corundum is commonly used as an abrasive for grinding media, sandpapers, cutting applications, and polishing compounds.
  • It can also be used as a gemstone in various forms of jewelry.

Spiritual Properties

Red Synthetic Corundum Ruby Stone.
Red Synthetic Corundum Ruby Stone.
Image Source: Wuzhou Qianjian Jewelry Co., Ltd.
  • Corundum helps to bring spiritual wisdom, protect against psychic attacks, get closer to your purpose of life, and heighten concentration.
  • These stones can subdue emotional tumult, enhance intuition, relieve tension, and create harmonious relations with the outside world.
  • It also helps to boost metabolism, normalize eye pressure, improve blood circulation, and stimulate the activity of the endocrine glands.


  • Corundum has an adamantine to vitreous luster and a specific gravity of 3.95-4.10.
  • These stones have an irregular/uneven and conchoidal fracture.
  • As it has the hardness of 9 on the Mohs scale, it can scratch almost any other minerals.
  • It has a white streak and a brittle tenacity but has no dominant cleavage.

Jewelry Stores Near You

  • Zales, Grand Junction, Colorado, USA
  • Maison Birks, Toronto, Ontario, Canada
  • Bentley & Skinner, London, England

Online Stores

  • Canadian Jewelry Exchange, Kelowna, Canada
  • With Clarity, New York, USA

Visit Stoneharu for more information about stones and gems.