Far before the development of gemmology as a science, all red gems were called Ruby. Interestingly the Moghuls of India were able to distinguish the nearly identical ruby (red corundum) and red spinel well before then. This was important as the Spinel was the most prized gem at the time and far more valuable than the red corundum we call ruby today.
Sold recently at Christie's for a cool €5 Million. Image credit Christie's
With eleven polished spinels, weighing a total of 1,131.59 carats, to the yellow gold link backchain and hook clasp, probably mounted in the 19th Century, 52.0 cm
Three of the spinels are engraved. Two with the name of Emperor Jahangir, one with the three names of Emperor Jahangir, Emperor Shah Jahan and Emperor Alamgir, also known as Aurangzeb:
JAHANGIR SHAH AKBAR SHAH 1015 1607 JAHANGIR SHAH AKBAR SHAH 1017 1609 JAHANGIR SHAH AKBAR SHAH 1018 1610 ALAMGIR SHAHI 1070 1660 SAHIB QIRAN ... 1045 1636
Mughal emperors have had, for centuries, a particular love for precious stones. The references found in numerous memoirs and chronicles of this period show the strong cultural belief in gemstone properties. The Timurids, ancestors of the Mughals, had begun the tradition of engraving titles and names on stones of outstanding quality and, along with diamonds and emeralds, large spinel beads were certainly their favourite. Emperors were commissioning special officials to search for spectacular stones with no expense spared, that they would then wear in multpiles to adorn their outfits. As much as these gems were a symbol of the opulence and dignity of the empire, they were also treasured as protective talismans.
These spinels were mainly originating from the Badakhshan mine, in the 'Pamir' region (on the frontier between Afghanistan and Tajikistan). This province gave its derived name to spinels, described as 'Balas rubies' for decades. The chemistry would demonstrate during the 19th Century that spinels and rubies are two different gems, but for long, any red stones were described as 'ruby'. Hence, it is interesting to note that among the most famous historical engraved spinels are the 'Timur Ruby' (in fact a spinel), now in the Royal Collection of HM Queen Elizabeth II of England. Its numerous and long inscriptions give a rare insight into its history, including the name of Emperor Jahangir, and although it is now known that the stone is a spinel, its name has not been changed. Another important engraved spinel is the Carew Spinel, currently in the V&A Museum, inscribed with the names of Emperors Jahangir, Shah Jahan and Aurangzeb.
Ruby and Spinel are very similar in appearance - they grow under the same conditions and locations, get their red colour from the same element (chromium) and they both fluoresce. So how did they know the difference way back then?
There are three “tells” an experienced gem trader uses to distinguish the two gems: their rough crystal shape, the gems shine (lustre), and colour.
Ruby Crystal in Marble. Credit GIA
Octahedral Spinel crystal. Credit GIA
Tell 1: Ruby and Spinel have different crystal structures: it is easy to distinguish fully formed rough crystals - the ruby forms a hexagonal crystal, the spinel forms as an octahedron (a double-sided pyramid).
Tell 2: Ruby is harder and will take a better polish. Even broken or worn red pebbles of ruby will be slightly shinier than the duller spinel. This is most likely why the large spinel were tumble polished in their original shape rather than faceted.
Tell 3: Even a cut gem has a tell! A ruby is pleochroic - this means that depending on the angle it may show a purplish-red or an orangish-red color. Spinel on the other hand is not pleochroic and will show the same colour viewed in all directions. In some cases holding a gem up to a bright light (the sun) and turning it around in all directions is enough to reveal the pleochroic colours of a gem. In other cases, a simple polarizing filter can help spot the difference. Find out more about pleochroism from the GIA.
Interestingly Spinels were mistranslated into English as rubies and it wasn’t until the arrival of gemmological equipment that western cultures learned that their crimson red crown jewels weren’t rubies but spinel!
Fun fact: Not all spinel is red - it comes in a wide variety of colours.
Ruby Crystal in Marble. Credit GIA
