Is that a real stone dial? A guide to natural, treated, and created stones

Buffy Acacia

Stone dials have been a slow burning trend all year, but the past couple of months have seen them hit a rapid peak of popularity. The fact that they’re surprisingly affordable to manufacture is a part of it, but also a modern obsession with varying colours and textures. However, more attention demands more awareness. Not all stones are created equal in a very literal sense, and understanding their differences will be key as more and more stone dials find their way into mainstream releases.

What counts as a stone dial?

In the worlds of gemstones and jewellery, there are a lot of things which are considered gemstones, even if they’re not technically stones. Organic substances such as pearl, amber and coral count, as do man-made products like glass and lab-grown crystals. A gemstone is defined by its decorative use, rather than its chemical composition. Much of that attitude stems from history, as people used those materials in jewellery without knowing or caring if it was a “real” stone before scientific analysis came along. Debating what should and shouldn’t be considered a real stone dial is kind of a pointless exercise when they all serve the same purpose, but that doesn’t mean you shouldn’t know the differences to make informed decisions.

Natural stones

It’s fairly self-explanatory, but a natural stone is something that was dug out of the ground and pretty much left as is. It may also be what you automatically assume anything referred to as a ‘stone dial’ is, but you could be mistaken. Some of the most popular natural stones in watchmaking right now are malachite, lapis lazuli, green aventurine, and turquoise, with carnelian, onyx, tiger’s eye and opal also being staples of stone dials since the 1960s. Most of them are forms of quartz or other plentiful minerals and aren’t rare in the slightest, even those like lapis lazuli which has clung onto its ancient reputation of preciousness. Even black opal, which is one of the most expensive gemstones per carat in the world, can go quite a long way when sliced as thin as a watch dial.

Mother-of-pearl

The use of mother-of-pearl as a dial material predates wristwatches, and can be found on antique pocket watches and clocks from centuries ago. Whether or not it counts as a ‘stone’ is more debatable. It’s made of mollusc shell, and the substance which causes the pastel iridescence is called nacre. When a natural pearl forms, it’s made out of that same nacre, hence the name mother-of-pearl. As a naturally-occurring product with every sample being unique, I would be happy to classify it as a stone dial because it ticks all of the same boxes. Your opinion may differ, but that’s how it’s classified in most areas of jewellery.

Treated stones

There are heaps of cool looking rocks which can come straight out of the ground, but the majority of them need a little help to look their best. Considering the amount of work which goes into selecting, cutting, and polishing stones for watch dials, it would be silly to think that your dial is truly ‘untreated’ to begin with. Common treatments for stone watch dials include lacquering and acid etching, while other areas of jewellery or crystal collecting may include dyeing and heat treatment. If you want the texture from a stone but desire a different colour, than applying a translucent lacquer is an easy way to give it a tint. Meteorites actually look quite boring before being etched with acid, otherwise you can’t see the famous Widmanstätten patterns, and it would just seem like a random slice of dark metal.

Created stones

Man-made can be considered somewhat of a derogatory term when compared with the Earth’s natural treasures, but humans have created some pretty special things. Aventurine glass is probably the best example of a man-made stone dial, because its dark colour and glittering metal dust is such a perfect evocation of a clear night sky. Outside of watchmaking, it’s known as blue goldstone. Lab-grown sapphire and spinel have also been used for see-through dials.

The verdict

To be clear, there is nothing inherently wrong with stones that aren’t 100% natural. Aventurine glass wouldn’t be so popular if it wasn’t beautiful, and some stones are just too boring to look at without treatment. A good example in the world of crystal specimens is low-grade amethyst geodes which are heat treated and labelled as citrine, even though citrine doesn’t naturally form in geodes. It’s always important to know exactly what you’re buying, especially if finding out a dial was man-made later on would ruin it for you. Thankfully, it doesn’t seem like outright fake stones like layered resin have made their way into the watch world yet, and beautiful natural examples are still affordable enough to manufacture that they don’t need to.