Buying guide

Ruby

Pigeon blood, a vivid pure red with a faint blue undertone and strong fluorescence, is the benchmark grade. Certification from GUILD, GRS or SSEF matters most above 1 carat, where price per carat rises steeply.

Ruby at a glance

Mineral family: Corundum
Chemical formula: Al2O3
Mohs hardness: 9
Refractive index: 1.762 - 1.770
Specific gravity: 4.00
Crystal system: Trigonal
Colours: red, pink
Birthstone month: July
Anniversary: 15th & 40th
Typical treatment: Heat treatment is near-universal and stable. Lead-glass filling is a separate, lower-value treatment that must always be disclosed.
In stock now: 9 stones from $194.00

What drives the price

In one line: Colour (pigeon blood premium), treatment status, clarity, size.

Treatment

Heat treatment is near-universal and stable. Lead-glass filling is a separate, lower-value treatment that must always be disclosed.

Any seller unwilling to state treatment in writing is telling you something. Every listing on this site states it.

Durability and daily wear

Extremely durable. Safe for ultrasonic cleaning unless the stone is glass-filled or heavily fractured, glass-filled rubies must only be cleaned with soap and water.

Mohs 9, trigonal crystal system, specific gravity 4.00.

Tradition and meaning

A stone of vitality, courage and passion. Associated with the root chakra and with protective, energising intent.

Birthstone for July. Associated with Cancer and Leo. Anniversary stone: 15th & 40th.

Frequently asked

What does pigeon blood ruby mean?

It describes the top colour grade: a vivid, saturated pure red with a slight blue secondary hue and strong red fluorescence under daylight. The term is applied by laboratories such as GUILD and GRS and carries a substantial price premium.

Is a heated ruby still natural?

Yes. Heat treatment mimics geological conditions, is permanent and stable, and applies to the large majority of rubies on the market. Unheated stones of good colour command a significant premium.

What is a glass-filled ruby?

Low-grade corundum whose fractures have been filled with lead glass to improve apparent clarity. It is a legitimate product when disclosed, but it is far less valuable and less durable than heated ruby, and it cannot be cleaned ultrasonically or resized with heat.