Urban Sterling

Urban Sterling Mason Mignanelli • Conceptual jeweller. Narrative-driven silver and gold work. Newcastle studio open, DM for appointments. Read my book ↓

03/06/2026

Because the colour of an opal isn’t chemical, faking it is very difficult. You can’t just dye a rock. To fake an opal, scientists literally had to figure out how to grow microscopic silica spheres in a laboratory and stack them together.

These are called Gilson Opals, and they are optically identical to the real thing. But they have one visual flaw that gives them away: they are too perfect.

In nature, the silica spheres settle in organic patches of colour. But in a laboratory, the spheres stack in highly organised columns.

If you look at the side of a Gilson opal under a jeweller’s loupe, the colour patches don’t look like organic flashes, they look a chain link fence or a piece of scaly lizard skin.

01/06/2026

Nephrite has a massive advantage in “fracture toughness,” making it one of the toughest stones on Earth. But ancient cultures didn’t just use this to make pretty statues, they also made weapons out of it.

Thousands of years before the Bronze Age, cultures across the globe realised that if you hit a piece of flint or quartz against a tree or a bone, it shatters. But if you carve a battleaxe or a heavy club out of nephrite, those tangled mineral fibres act as a natural shock absorber.

You could literally smash a nephrite weapon against a solid wooden shield with full force, and the stone would not break. Long before we had steel, the most high-tech military hardware on the battlefield was a piece of “soft” green jewellery.

31/05/2026

I mentioned in the video that the Black Prince’s Ruby in the British Imperial State Crown is actually a massive red spinel. But I didn’t mention its insane military history.

This stone wasn’t just sitting safely in a glass case for its whole life. In 1415, King Henry V had this 170 carat spinel set directly into his battle helmet. During the Battle of Agincourt, the King was struck squarely on the head by a French battleaxe. The blow was so violent it sheared off part of the helmet, but the King survived, and incredibly, so did the stone.

It survived centuries of medieval warfare, fires, and theft, eventually taking its place right in the front cross of the Imperial State Crown. It might hold the title of the “Great Imposter,” but considering the violence this rock has survived, it is one of the toughest, most legendary gemstones in human history.

Recent custom work - Double heat treated & oxidised Argentium silver w/ flush set Ruby
30/05/2026

Recent custom work - Double heat treated & oxidised Argentium silver w/ flush set Ruby

28/05/2026

I tell my people this all the time: if you want a financial investment, do not buy jewellery. Go buy a 1-ounce 24ct bullion coin and put it in a safe.

Modern fine jewellery is an aesthetic purchase, an emotional heirloom, and a piece of wearable engineering. When you buy a bespoke ring, you are paying a massive premium for a craftsperson to bend a stubborn, raw element to their will so you can safely wear it on your hand for the next fifty years without the stones falling out.

You are buying functional art. You don’t look at a # painting and calculate its value based on the wholesale cost of the canvas and the oil paint. You shouldn’t do it with your jewellery either

25/05/2026

I mentioned in the video that rose gold is just yellow gold pushed warmer by adding copper. But what I didn’t mention is that it wasn’t always called rose gold.
In the 19th century, it was known globally as “Russian Gold.”

The famous jeweller Carl Fabergé was one of the first to heavily incorporate this copper heavy alloy into his bespoke pieces, most notably in his legendary Imperial Eggs. Because the Russian elite were the only ones commissioning and wearing it, that distinct, coppery pink hue became entirely synonymous with their empire.

The name “Rose Gold” is a relatively modern marketing rebrand.

24/05/2026

I mentioned in the video that Mystic Topaz gets its colour from a process called Physical Vapour Deposition (PVD). But this technology wasn’t actually invented to make cheap rocks look pretty. It was invented for heavy industry.

If you walk into a hardware store and look at high end drill bits or saw blades, you will notice they often have a bright gold or iridescent sheen to them. That is a PVD coating of Titanium Nitride. Industrial manufacturers use it because it creates a hard, microscopic surface layer that reduces friction and extends the life of cutting tools.

At some point in the 1990s, the jewellery industry realised that if they used this machinist’s trick and applied it to the bottom of a cheap, colourless Topaz, it would act like an iridescent mirror.

When you buy a Mystic Topaz, you aren’t buying a rare geological phenomenon. You are wearing the exact same surface treatment used to coat a masonry drill bit.

21/05/2026

Engineers take a YAG crystal, remove a tiny fraction of the Yttrium atoms, and replace them with Neodymium to create a laser.

But what does an Nd:YAG laser actually do?

Because the Yttrium “engine block” is so rigid, this crystal can handle an absolutely crazy amount of energy without shattering. When you pump it with high intensity light, the Neodymium atoms get excited and fire off a beam of infrared radiation.

That beam is so powerful and precise that it is the backbone of modern heavy industry and medicine.

If you go to a clinic to have a tattoo blasted off your skin, the machine they use is an Nd:YAG laser. If you watch a robotic arm slice through a half-inch sheet of solid titanium in an automotive factory, that’s also an Nd:YAG laser.

20/05/2026

In 1942, the government banned platinum for civilian jewellery because it was a “strategic war material.” But the military wasn’t making engagement rings. What did they actually need it for?

Chemistry and engines.

Platinum is one of the greatest chemical catalysts on Earth. This is why another platinum group metal (palladium) spiked so hard in price a a while back, it was needed for making catalytic converters.

During WWII, it was desperately needed to manufacture high octane aviation fuel and the nitric acid required for explosives. Without platinum catalysts, bomber planes couldn’t fly, and artillery shells couldn’t be made.

Furthermore, platinum is incredibly heat-resistant and doesn’t corrode. The military needed massive amounts of it to build the heavy duty spark plugs for combat aircraft engines, ensuring they wouldn’t melt or misfire at high altitudes.

If you were a civilian demanding a platinum wedding band in 1942, you were quite literally depriving an aircraft engine of the parts it needed to stay in the sky. So, the jewellery industry pivoted to white gold, and an entire new aesthetic was born.

18/05/2026

I mentioned in the video that 24-carat gold is close to useless for fine jewellery, but people always say, “Wait, didn’t the ancient Egyptians and Romans use pure gold?” Yes, they did. But ancient jewellery was incredibly chunky, heavy, and usually featured bezel-set stones where massive walls of metal held the gem in place.

Modern engagement rings are completely different.

Lots of people today want delicate bands and tiny, microscopic prongs so the stone looks as exposed as possible. If I made a modern, four-prong engagement ring out of pure 24k gold, it would be a disaster.

Pure gold is so soft you can literally bend it with your fingernail. The first time you reached into your purse or bumped your hand on a steering wheel, those pure gold prongs would simply peel back like a banana, and your diamond would hit the pavement.

We don’t drop the purity to 18k or 14k to save money. We do it to make sure the ring survives longer than 6 months.

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39a Beaumont Street
Newcastle, NSW
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