How To Spot A Fake: Sapphire | The Diamond Reserve

How To Spot A Fake: Sapphire

In this month’s entry in our ‘how to spot a fake’ series, we take a stab at the jewel of the sea and the harbinger of prosperity, the sapphire.

Unlike the other posts in our series, this one is an absolute doozy. To put it simply, fake sapphires can be very difficult to spot. We’ll walk you through the easiest methods, starting with the simplest one that anyone can perform. But first:

Why Are They Hard To Spot?

Fake Sapphires are typically filled with Lead Glass, which has an uncanny resemblance to actual sapphire. The fact that they’re glass makes it a little easier, but fake sapphires are extremely vulnerable to cleaning chemicals. Because of this, the fake ones can crack and break entirely. With that said, let’s take a look at how to spot the difference.

The Fog Test

If you’re looking at a sapphire and want to confirm it’s authenticity, just breath on it for a second. On real sapphires, the fog from your breath will evaporate very quickly (~2 seconds). If it’s fake, it may take 5 seconds or more to start evaporating and 2-3 seconds to actually evaporate. By doing the fog test, we’re exploiting the fact that fake sapphire is almost always glass, which retains moisture better than sapphire.


Back to exploiting the mechanics of glass, one big weakness of glass fakes is that they form bubbles inside the “gemstone”. Look closely at the sapphire and see if you can spot any bubbles inside. These are just pockets of air that are trapped during the creation of the glass. It’s almost impossible to make glass without any air pockets inside, though they may be tiny.

Too Perfect

Synthetic sapphires, also referred to as “flame fusion sapphires,” have the flaw of being too flawless. Anything synthetic will have no inclusions or flaws whatsoever. If the stone doesn’t have a single chip or scratch anywhere on it then you don’t want it.

Want to take the worry out of shopping for a gemstone? Give us a call at (720) 560-3548 or book an appointment to get started!