Ruby Crystal Madagascar Natural Red Corundum Mineral Specimen 5-20mm Genuine Collector Display Stone with Certificate of Authenticity

Natural Ruby Crystal – Madagascan Red Corundum Specimen

This genuine Ruby crystal from Madagascar is a natural red variety of corundum, carefully selected for colour, integrity, and display quality. Each specimen measures approximately 5–20mm, making it ideal for collectors seeking smaller cabinet pieces, study samples, or gemstone-grade mineral examples. The photograph shows an example of the actual specimen you will receive. Please refer to the listing images for full sizing and expected appearance within this size range.

Your Ruby includes a Certificate of Authenticity lifetime guarantee generic card, confirming it is a 100% genuine natural mineral specimen.

Mineral Species & Chemical Composition

Ruby is the red variety of Corundum, composed of aluminium oxide with the chemical formula Al₂O₃. It belongs to the oxide mineral group and crystallises in the trigonal crystal system.

The red colour is caused by trace amounts of chromium replacing aluminium within the crystal lattice. The intensity of the colour can range from pinkish-red to deeper crimson, depending on chromium concentration and geological conditions during formation.

Corundum is one of the hardest natural minerals, ranking 9 on the Mohs hardness scale, second only to diamond. This exceptional hardness contributes to Ruby’s durability and long-standing recognition as a highly valued gemstone mineral.

Geological Formation – Madagascar

Madagascar is one of the world’s most important sources of Ruby and other corundum varieties. Rubies from this region are commonly formed in high-grade metamorphic environments, particularly within marble-hosted deposits or aluminium-rich metamorphic rocks.

During metamorphism, intense heat and pressure cause recrystallisation of original sedimentary or igneous materials. Under the right chemical conditions, aluminium oxide crystallises into corundum. When chromium is present, the crystal develops the red coloration that defines Ruby.

Madagascan deposits are known for producing vibrant, naturally coloured material with varied crystal habits. Associated minerals may include calcite, feldspar, spinel, mica, and amphibole depending on the host rock.

Colour, Structure & Physical Properties

These 5–20mm Ruby specimens display natural red to pinkish-red tones typical of Madagascan corundum. Individual pieces may vary slightly in shade, transparency, and surface texture due to natural geological formation.

Key mineralogical properties include:

• Mineral Group: Oxide

• Species: Corundum (Ruby variety)

• Chemical Formula: Al₂O₃

• Crystal System: Trigonal

• Colour: Red to pinkish-red

• Lustre: Vitreous to subadamantine

• Transparency: Transparent to opaque depending on crystal quality

• Hardness: 9 Mohs

Natural inclusions, growth zoning, or surface irregularities are common and are part of the crystal’s authentic geological character. These specimens have not been artificially dyed or treated.

Collecting, Study & Display

Smaller Ruby crystals in the 5–20mm range are ideal for mineral collectors, gemstone enthusiasts, and educational purposes. Their compact size makes them suitable for display boxes, mineral trays, study collections, or inclusion in curated gemstone assortments.

Ruby has been traditionally associated in spiritual practices with vitality and courage; these associations are cultural rather than scientific.

Its rich red colour and exceptional hardness make Ruby one of the most recognisable and historically significant gemstone minerals in the world. Madagascan material remains especially sought after due to its strong natural colour and reputable locality.

Authenticity & Individual Selection

Each Ruby crystal is a carefully chosen genuine specimen. The listing photograph shows an example of the actual piece you will receive within the stated 5–20mm size range. Please review the images for scale and expected appearance.

Every specimen is supplied with a Certificate of Authenticity lifetime guarantee generic card, confirming its genuine natural origin.

A classic example of Madagascan corundum, this Ruby crystal represents the remarkable geological forces of metamorphism and stands as a compact yet highly collectible mineral specimen suitable for both new and experienced collectors.