Before the rise of modern gemmology in the late 19th and early 20th centuries, it was often believed that rubies and spinels were the same stone as they are often found in the same mines. Nevertheless, these two minerals are quite distinct and chemically different. Subsequently, as jewellery owners were told some of their treasured rubies and sapphires were actually spinels, the stone’s reputation suffered.
Until recent times, spinel was a relatively unknown gem species with consumers and as such it has long been underappreciated. Of late, an increasing demand for ruby alternatives has not only rekindled an appreciation for spinel’s rich red colour and history, but has brought about an awareness of the wonderful range of colours it is produced in. It may be colourless, but is usually various shades of pink, rose, red, blue, brown, black, or (uncommonly) violet, with red being the most valuable. There is a general absence of green and yellow stones.
In ancient times, the mines of central and southeast Asia yielded exceptionally large spinel crystals. These fine stones became known as Balas rubies, and some of them were the treasured property of kings and emperors, often passing through many hands as spoils of war. As a result, some of the world’s most illustrious “rubies” are actually spinel.
One of the most famous examples is the “Black Prince’s ruby”, this historic crimson-red gem set in England’s Imperial State Crown and displayed in the Tower of London. It first appeared in the historical records of fourteenth-century Spain, and was owned by a succession of Moorish and Spanish Kings before Edward, Prince of Wales, the “Black Prince”, received the stone in 1367 as payment for a battle victory. Since then, many other English monarchs, including Henry VIII have cherished the gem. It has outlasted them all, surviving fires, attempted theft, and World War II bombing raids, to become, with the Koh-i-Noor diamond, one of the centrepieces of England’s Crown Jewels.
Another large spinel in the Crown Jewels is the “Timur ruby,” weighing over 350 carats. It, too, has a chequered history. Several Persian inscriptions carved into the gem testify to its age.
Found traditionally and mainly in Afghanistan, Myanmar, and Sri Lanka, spinels have been discovered more recently in various sites in Africa, Australia, Russia, and Vietnam. These gems are usually not mined from the hard rock primary deposits in which they form but instead from alluvial or placer deposits where eroded material has been washed downstream.
Natural spinels in today’s market are almost all untreated. Their relatively modest prices, availability in an array of colours, hardness, and suitability for most types of jewellery make them even more inviting.
Spinels are generally free of inclusions, but some inclusions are distinctive. Fine Octahedral-shaped inclusions are the most common feature of spinels from all sources.
Regardless of colour, spinel’s high refractive index ensures excellent brilliance and fire in a well cut and polished stone. Spinels are hard and durable gemstones (8 on Moh’s scale of hardness) and make a good choice for almost all jewellery applications.
Leonard Joel is delighted to be auctioning beautiful spinel set jewellery in our June Fine Jewels auction on Monday 1st June 2020.
Julie Foster / Head of Jewels