What comes to mind when you think about spinel? I personally think that it gets a hard rap - largely because the spinel that we typically see in the Western vintage and antique jewellery market is synthetic spinel.
So let's talk about synthetic spinel for a minute, shall we? I'll call it syn spin, because that's more satisfying. Syn spin was created in 1908 quite accidentally when synthetic sapphire was being developed (they were originally created by the same, relatively straight forward Verneuil Flame Fusion method).
Syn spin is extremely low cost to produce, and can be created in almost any colour. Post creation treatments can make it appear as a convincing replacement for some gemstones you may not expect, like moonstone or lapis lazuli.
Interestingly, unlike most synthetic gemstones (like sapphire, ruby, emerald), synthetic spinel isn't actually chemically identical to natural spinel.
Perhaps this is why syn spin lacks the charm of natural spinel?
Natural spinel is a highly revered gemstone in many parts of the world, notably the Indian subcontinent where it can originate from (in fact, most of the good stuff never makes it out of the domestic markets!). It is highly valuable, especially in red and blue tones, competing with the finest rubies and sapphires in price.
One of the reasons it holds such allure requires a little trip down gemmology lane, but i'll boil it down as much as possible.
When we talk about gemstones, we can classify them into one of two groups: singly refractive and doubly refractive.
Singly refractive means that when light passes into a gemstone, it travels through it (and refracts back out) in one beam of light.
Doubly refractive means that the beam splits into two when it travels through a gemstone.
Most gemstones you can think of are doubly refractive (sapphire, ruby, emerald, tourmaline, topaz, chrysoberyl)
There are far fewer singly refractive gemstones - diamond, the garnet family, spinel are the main transparent singly refractive gemstones you will find in jewellery.
What does this mean? Simply put, it means that the colour of a spinel will appear the same from all angles. It is pure colour.
If I have a pink sapphire and a pink spinel, and walk to the end of your garden and hold both in the air, you're going to see the pink in the spinel much more easily than the sapphire.
Pretty cool, right?
So, when you come across natural spinel, do pause to marvel at its colour, and the inclusions & subtleties of colour that only natural gemstones can convey. It's a stone that I love to work with, and have done recently in this lilac-pink spinel chain ring.
