Coloured stone grading is less standardised than diamond grading.
There is no single universal scale. But within each stone family, certain colour descriptions have come to define the absolute peak of what that stone can be. These are three of them.
How colour grading works for coloured stones
For diamonds, the hierarchy is well established: cut first, then colour and clarity, then carat weight. For coloured stones, the hierarchy shifts. Colour is the primary driver - the saturation, hue, and tone of the stone matters more than anything else.
A ruby with exceptional colour commands a premium over a larger ruby with ordinary colour. This is why these descriptors matter. They are not marketing language. They are shorthand for a specific, recognised quality standard within the trade.
Pigeon Blood Ruby
Pigeon Blood is the trade term for the most coveted colour in a ruby: a vivid, deeply saturated red with a blue undertone that creates depth within the stone. The name is historical, used in the Burmese gemstone trade for centuries.
The finest Pigeon Blood rubies historically came from the Mogok region of Myanmar. High saturation, no brown or orange tones, and an intensity that deepens under incandescent light. This is the specific colour profile HEIREST replicates in its lab-grown rubies.
Royal Blue Sapphire
Royal Blue is the descriptor for the most sought-after sapphire colour: a rich, deeply saturated blue associated with the legendary Kashmir-origin stones - from a deposit now largely exhausted, whose colour has defined the premium end of the market for over a century.
The characteristic of Royal Blue is a velvety depth that distinguishes it from lighter or more violet-toned sapphires. Saturated, but not dark. HEIREST's lab-grown Royal Blue Sapphires are grown to replicate this specific profile.
Zambian Emerald
Unlike the ruby and sapphire descriptors - which refer to colour alone - the Zambian designation refers to a colour profile associated with a specific origin. Zambia is one of the world's leading sources of fine emeralds: deep, slightly bluish-green, with higher clarity than many other origins.
Zambian emeralds carry a slightly cooler, deeper green than Colombian equivalents. In a lab-grown context, the Zambian descriptor refers to the colour character being replicated - that depth and cool tone - rather than the geography.
Why HEIREST chose these three
Each represents the peak colour grade within its stone family. Not the most accessible - the finest.
The decision to offer Pigeon Blood, Royal Blue, and Zambian Emerald reflects the same standard we apply to diamond specification: set the benchmark high, and hold to it.
For each coloured stone, HEIREST confirms colour, material, and cut. IGI certification is available on request.
