Education Centre

Education Centre


The ‘king of gems’. Ruby is one of the world’s oldest, most revered gemstones and one of the rarest.

The mineral Chromium is responsible for the gems startling colour. Rubies with hardly any inclusions are so rare that large stones fetch higher prices at auction than even diamonds.

Fiery and romantic, showing brilliant depth and intensity, the red hue of Ruby is certain to draw attention. Its symbolic association with passion makes it a stunning choice for natural spice designs. In settings that focus attention on voluptuous colour, Ruby sends a message of drop-dead glamour and femininity.

As the US birthstone for July, and the world’s best-known and best-loved red gem, ruby still captivates the hearts and imaginations of gem professionals and consumers alike.

General Info

Major Sources

Thailand, Myanmar, Kampuchea, Sri Lanka, Kenya, Afghanistan, India, Pakistan, Tanzania, Madagascar.


Environmental Factor


 HeatHigh heat can cause a change in colour or clarity; it can also damage or destroy fracture- and cavity-fillings.
 LightGenerally stable, but heat from bright lights can cause oil to leak or dry out.
 ChemicalsCan harm fillings and remove oil; soldering flux containing boron, and fire coat made with boric acid powder, will etch the surface ofeven untreated stones.

Quality Information

  • C2 - Commercial quality; included; variation in colour
  • B - Included; light pinkish red; good cut, good polish
  • A - Slightly included; medium pinkish red; good cut, good polish
  • A+ - Eye clean; medium to medium dark pinkish red; good cut, good polish
  • AAA - Eye clean; Medium dark pinkish red to red; brilliance; excellent cut, good polish



9 on the Mohs scale


Usually excellent, but stones with certain treatments or large fractures or inclusions can be less durable.


Rubies are rated ‘excellent’ for everyday wear. Avoid exposure to heat and contact with chemicals.

To clean, gently scrub with a soft toothbrush and a solution of mild dish soap and warm water, or clean in an at-home ultrasonic unit.

Further care instructions