GEM LIBRARY
Sapphire

Sapphire

藍寶石

Sapphire is not always blue — within corundum, every colour but red is called sapphire. Many people wear one for years without ever knowing this.

TypePrecious gemstone
FamilyCorundum
Hardness9
ColourBlue · Pink · Yellow · Purple · Colourless · Orange
BirthstoneSeptember

Sapphire is every colour of corundum except red — within the corundum family, all but red (ruby) is called sapphire, Mohs hardness 9. It is the most versatile of the coloured gemstones and the best suited to daily wear. Heating is the norm; beware diffusion treatment. It is September’s birthstone.

About Sapphire

Sapphire and ruby are the same mineral, corundum, at hardness 9; iron and titanium turn it blue, while pink, yellow, purple, orange and colourless are together called fancy sapphire. Within corundum, only the red is ruby; every other colour is sapphire. Hard and tough, it is the coloured gemstone best made for everyday wear.

Why Choose a Sapphire

Sapphire is September’s birthstone, a symbol of loyalty and wisdom, and its use in royal engagement rings adds a story of its own; with many colours and high hardness, it is the most versatile of all. The pink-orange “padparadscha” (lotus sapphire) is the rarest and most coveted colour — a warmth caught between sunset and lotus flower.

History & Famous Stones

Sapphire has been the stone of loyalty and wisdom since antiquity — seen in royal engagement rings and museum centrepieces alike; its most storied origins are Kashmir and Ceylon (Sri Lanka). A few legendary sapphires are names of the auction room and the museum:

The Truth About Sapphire

Heating is the norm (declared, it is normal); beware diffusion treatment, especially beryllium diffusion; origin and heat status move the value.

Sapphire on the Market

Tell apart natural (unheated / heated), diffusion-treated, padparadscha and synthetic; prices vary enormously, and the certificate is key.

TypeTraitsPriceHow to tell
Natural · unheatedNatural colour + origin reportHighestReport reads “no heat”
Natural · heatedStandard, more even colourHighReport notes heating
Diffusion (incl. beryllium)Surface-coloured layerLowReport reads “diffusion”
Padparadscha (lotus)Pink-orange, rareHighCertificate, natural colour
Synthetic / glassToo perfectLowCertificate, inclusion traits

Before You Buy

Choose a sapphire for beauty of colour over depth of colour; heating is acceptable, diffusion must be priced apart; padparadscha and “unheated” both rest on the certificate.

FAQ

Is a sapphire always blue?

No. Every colour of corundum but red (which is ruby) is called sapphire — including pink, yellow, purple, orange and colourless, together known as fancy sapphire.

Is heating a sapphire normal?

Yes. Heating is standard in the trade and, honestly declared, legitimate. What to guard against is diffusion treatment (especially beryllium diffusion), which is worth far less.

What is padparadscha?

A pink-orange "lotus" sapphire — the rarest and most sought-after colour of all, to be confirmed by certificate.

Can I wear a sapphire every day?

Yes. At hardness 9, second only to diamond, and tough as well, it is the most hard-wearing of the coloured gemstones.

How do I clean a sapphire?

Warm water and a soft brush; an unfilled sapphire generally takes ultrasonic, though avoid it if there are obvious fractures.