Rock crystal: April’s other birthstone

Rock crystal is beautiful, powerful and has been used in adornment for thousands of years. It is April’s less famous, but no less beguiling, birthstone. My birthstone for April is diamond or rock crystal. I remember finding this out when a child and being quite pleased, thinking diamonds are expensive! Somehow I thought that caché… Continue reading Rock crystal: April’s other birthstone

Heamatite in quartz

Haematite streak inside quartz boulder

I love haematite (also spelled hematite). This iron oxide mineral is the original mirror, having a highly polishable metallic lustre (while also dull and earthy in rough form), usually greyish-brown to silverish-grey to nearly black, and an inner core of blood red, hence the name. Haematite crystallises in the trigonal crystal system, the same as… Continue reading Heamatite in quartz

Colour in gemstones: quick notes

Some useful hand notes to distinguish terminology used to describe the optical effects that cause colour and colour phenomena in gemstones. It’s important to know your spectral colour effects like fire and iridescence and distinguish between pleochroism, iridescence and colour change. The cover image shows the two body colours (dichroism) that combine in a ruby:… Continue reading Colour in gemstones: quick notes

Spinel: quick notes

The lesser-sung cousins of corundum like sapphires and rubies, spinels are resilient gemstones that come in a variety of colours from greys and purples to ‘Jedi’ red. Here are some quick geological facts to get you started with this beautiful gem material. Note: Don’t get confused with synthetic (lab grown) spinel, commonly coloured blue with… Continue reading Spinel: quick notes

Where am I in the gemstone pipeline?

This is a reproduction of a reflective piece of writing I completed for my Gem-A Foundation in Gemmology in February 2022. Image above: Examining the strong dichroic (two-colour) pleochroism of a green tourmaline crystal using Gem-A’s London dichroscope with a flatlight (credit: Tehmina Goskar). What is the gemstone pipeline? The gemstone pipeline considers all of… Continue reading Where am I in the gemstone pipeline?

Why gems?

Cornish sunshine quartz

I have studied and enjoyed material culture all of my professional life, both as a curator and historian. One of my biggest pleasures is to research materials from their earthly origins to their use and appreciation in society today. During my doctoral research I was fortunate to have studied and written about the significance of… Continue reading Why gems?