1.52ct Australian Sapphire, Teal, Green, Blue, Yellow - Decagon

The world’s sapphires can be understood through two broad geological stories. Metamorphic sapphires — from classic sources such as Sri Lanka and Kashmir, and deposits in Southern Madagascar — formed deep within continental crust under immense heat and pressure. These origins are often associated with silky, pastel tones in velvety blues, bright pinks and the rarer purples.

Basalt-related sapphires — from Australia, Thailand, and Northern parts of Madagascar — formed in deep magmatic environments and were carried to the surface by volcanic activity. They are sometimes described as darker or more saturated, but that is only part of the story. Australian sapphires occur in a remarkable range of colours, from bright blues and vivid greens to golden yellows, teals, orange and parti-coloured stones with natural bands of blue, green and yellow. Pink and purple are found rarely, and typically only in small sizes under 0.20ct.

Since 2005, we’ve worked almost exclusively with Australian sapphires, drawing from the Queensland gem fields around Anakie and Rubyvale, the New England district of NSW around Inverell and Glen Innes and when possible, the North East of Tasmania. Australian sapphire mining is typically small-scale and regulated, and our own supply chain is deliberately traceable — we often know both the miner and cutter.

Heat treatment is common across the global sapphire trade and is used to improve colour and clarity. When properly disclosed, we don’t see it as good or bad — simply part of a sapphire’s story. A beautiful heat-treated sapphire is still a beautiful sapphire; in many cases, treatment has revealed colour and brightness that may otherwise have remained hidden.

Some people prefer sapphires with no indications of heat, and we understand the appeal. Fine untreated sapphires, especially bright, lively stones, are rarer and usually more valuable, while others are treasured for the inclusions that reveal their natural character. But rarity is only one part of choosing a gemstone. What matters most is transparency: knowing whether a sapphire has been treated, what that means, and how it affects value.

For us, responsible sapphire sourcing is not about labels or shortcuts; it is about knowing each stone’s origin, treatment, character and value, then sharing that story with clarity and care.