Coloured Gemstones, Birthstones and Custom Gemstone Jewellery

Sapphire and ruby (corundum, 9 on the Mohs scale) and spinel (8) are among the most practical choices for daily wear. Softer or more brittle stones such as opal, tanzanite and emerald can still be worn, but they benefit from protective settings and more careful habits.

Yes, many are. Heating of sapphire and ruby and oiling of emerald are long-standing, widely accepted practices, while treatments such as glass filling affect durability and value more significantly. A reputable seller should always disclose known treatments.

A synthetic, or lab-grown, stone has essentially the same chemistry and crystal structure as its natural counterpart. A simulant only imitates the look, such as glass or cubic zirconia standing in for another gem.

It can. Certain origins, such as Kashmir or Burma for sapphire and ruby, carry strong reputations, but the stone's own colour, clarity and cut still matter most. Origin is determined by laboratory analysis of inclusions and trace elements rather than by appearance alone.

No. Stones that are porous, fracture-filled, oiled or heat-sensitive, including opal, emerald, turquoise and tanzanite, can be damaged. Warm soapy water and a soft brush is the safest general method.

Not quite. Carat is a measure of weight, and because sapphire is denser than diamond, a one-carat sapphire typically looks slightly smaller face-up than a one-carat diamond of the same shape.