I read this week that a shopping channel in the US is promoting a jewellery collection featuring cubic zirconia set in platinum.

This certainly departs from the norm; platinum is generally used in premium diamond jewellery, especially diamond rings. In the 18th Century Louis XV of France declared platinum to be the only metal fit for a king, and the spot price for platinum on the London Metal Exchange yesterday was about 30% higher than the spot price for gold.

The people marketing this range are calling it ‘premium’ jewellery, featuring ‘finest’ cubic zirconia. Can cubic zirconia be a premium product?

Cubic zirconia, or CZ, is a diamond simulant. Technically it’s the cubic crystalline form of zirconium dioxide. It’s a synthesized material – i.e. created in a laboratory – and it resembles diamond in that it’s hard, optically flawless and colourless (unless other materials are introduced to give it some colour).

CZ is a relatively hard material but nowhere near as hard as diamond. It can be brittle – more so than diamond – and it has a high refractive index (although not quite as high as diamond) and its dispersion of light actually exceeds that of diamond.

But CZ is denoted as having a subadamantine level of lustre, whereas diamond is adamantine, meaning that diamonds have the brilliant light reflection and transmission properties which we find so attractive.

So CZ has some impressive physical and optical characteristics – not quite as impressive an all-rounder as a diamond – but pretty good.

But CZ is a synthetic material from a lab rather than a natural mineral which might be as much as 4 billion years old.

And a diamond’s natural provenance gives it its individual character too because every stone is different, each with its tiny flaws and markings. Every single diamond is unique in a way that factory-produced CZ stones can’t really match.

Why is CZ popular? Why are so many millions of carats of CZ churned out each year? Because it’s cheap. It’s usually set in 9 karat gold, sometimes silver, pairing up quite logically and naturally with these more affordable metal settings.

But CZ stones set in platinum? Can the use of platinum turn cubic zirconia into a premium product? Well perhaps it can if it’s just one element of a complete premium package.

I think it’s a bit of a stretch. I reckon that CZ has been dragged too low by mass production and by widespread use in cheap jewellery for it to be raised convincingly into a premium jewellery category.

The range of CZ+platinum jewellery is reported as being priced from $150 to $1000, or about £90 to £600.

We say – perhaps unsurprisingly – that for a similar sum (from £70 to £500) you can hire a piece of beautiful diamondthrills jewellery, featuring brilliant diamonds and 18 karat gold, and enjoy the real thing rather than a cheap simulant.