How to Tell If a Spinel Is Real: A Complete Guide for Gem Lovers
Spinel is a gemstone that has often been mistaken for other precious stones like rubies and sapphires.
In short: Genuine spinel (Mohs 8) shows single refraction (unlike ruby/sapphire which double-refract) — a key distinguishing feature. Refractive index 1.71-1.74; specific gravity 3.58-3.61. Natural spinel comes in red, pink, blue, purple and black; the famous 'Black Prince's Ruby' in the British Crown Jewels is actually red spinel. Always insist on a GIA report.
Its vibrant colours and remarkable brilliance make it a favourite among gem enthusiasts and jewellers alike.
However, with the market flooded with both natural and synthetic spinels, it's essential to know how to distinguish between the two.
This guide will walk you through the characteristics of spinel and provide practical tips to help you identify a genuine stone.
Understanding Spinel
Spinel is a magnesium aluminium oxide mineral that crystallises in the cubic system.
It's renowned for its wide range of colours, including red, pink, blue, lavender, green, brown, black, and even colourless varieties.
Historically, spinel has been misidentified as ruby or sapphire due to its similar appearance and shared mining locations.
Notable examples include the "Black Prince's Ruby" and the "Timur Ruby," both of which are, in fact, spinels.
Why Synthetic Spinel Exists
The allure of spinel's beauty has led to the creation of synthetic versions, primarily through methods like flame-fusion (Verneuil process) and flux-melt.
These lab-grown spinels are often used as affordable alternatives in jewellery, mimicking the appearance of their natural counterparts.
