Phosphosiderite is an iron phosphate mineral in a delicious shade of orchid: lilac to lavender pink, often veined with creamy yellow. The clunky name simply describes its chemistry, phosphate plus sideros, the Greek word for iron. It is a fairly recent arrival in jewellery, with most gem material coming from Chile, along with Argentina and Portugal. Its colour sits in a sweet spot between pink opal and lavender jade, which is exactly why cutters fell for it.
This is a delicate stone: 3.5 to 4 on the Mohs scale and brittle, so it belongs in pendants, earrings and carefully worn beads rather than rings. Keep it away from heat, chemicals, ultrasonic cleaners and long soaks in water, and store it apart from harder gems. It is cut as cabochons and beads that show off its smooth colour. It is often confused with pink opal in both directions, so a seller who can tell them apart, like us, is worth having.
Pink-purple common opal can look pretty similar; lepidolite and kunzite share the lilac-pink palette.
