THE GEMHOOD LIBRARY
Gemstone encyclopedia
Learn about remarkable natural stones through factual guides, care advice, and their cultural and historical significance.
Sodalite
A blue rock-forming mineral commonly used as cabochons and beads, sometimes with white veining.
Read guide → Spinel group (MgAl₂O₄)Spinel
An independent mineral species occurring in a vivid range of colours, historically sometimes mistaken for ruby.
Read guide → Variety of zoisiteTanzanite
Blue-violet zoisite associated especially with a limited region of northern Tanzania.
Read guide → QuartzTiger's Eye
A golden-brown quartz gemstone valued for a mobile band of light called chatoyancy.
Read guide → Aluminium fluorosilicateTopaz
A durable silicate gemstone found in several colours; blue topaz is often treated and treatment should be disclosed.
Read guide → Complex borosilicate groupTourmaline
Tourmaline is a gem group offering a remarkably broad selection of colours. Pink, green and multi-colour examples are popular in jewellery, but individual stones can vary in treatm...
Read guide → Hydrated copper aluminium phosphateTurquoise
Turquoise has an opaque blue-to-green appearance and a long decorative history. Jewellery pieces can include natural matrix patterns or stabilised material. Sellers should identify...
Read guide → Zirconium silicateZircon
A natural zirconium silicate gemstone distinct from synthetic cubic zirconia, with attractive brilliance and varied colours.
Read guide → ZoisiteZoisite
A mineral species that includes blue-violet tanzanite and other gem varieties.
Read guide →Traditional and spiritual associations are presented for cultural interest, not as medical facts.