What Is “Flash” in Crystals? A Simple Guide to That Magical Gleam

If you’ve ever heard a crystal seller say, “Look at the flash in this one!” and wondered what they meant, you’re not alone! Flash in crystals is one of those beautiful little surprises that make collecting stones so exciting. But what exactly is it?

What Is Flash in a Crystal?

“Flash” refers to a sudden shimmer or shine that appears when the light hits the crystal at just the right angle. It can look like a bright gleam, a colourful streak, or even a hidden rainbow dancing across the surface. In some crystals, the flash is bold and obvious. In others, it’s more delicate and fleeting – there one moment and gone the next.

Why Is Flash Sometimes Hard to See?

If you’ve ever struggled to spot the flash in a crystal like Amazonite or Anhydrite, you’re not imagining things! These stones can have a very subtle flash, often silvery or soft blue, that only appears under certain lighting and angles. It can feel like a blink-and-you’ll-miss-it moment. That’s part of what makes it so special!

On the other hand, crystals like Rainbow Moonstone are famous for their bright and colourful flash. This glow (called adularescence) often shines with blue or rainbow hues that are much easier to spot, especially under natural light.

What Causes Flash in Crystals?

Flash in crystals is caused by the way light interacts with the mineral’s internal structure. In some stones, there are tiny layers or fractures inside that catch and reflect the light in a unique way. This can create effects like:

• Adularescence – the glow in Moonstone

• Labradorescence – the vibrant flash in Labradorite

• Chatoyancy – the “cat’s eye” effect in some stones

But for many crystal collectors and sellers, we call it “flash” – a simple word for something magical.

How to Spot Flash in a Crystal

To see the flash in a crystal, hold it under a good light (natural sunlight works beautifully), and tilt it slowly. Move it around a little – it often appears when you least expect it! Once you see it, you’ll know what all the excitement is about.

Popular Crystals That Show Flash:

• Rainbow Moonstone – bright blue or rainbow flash

• Labradorite – dramatic multicoloured flash

• Amazonite – soft shimmer or silver sheen

• Anhydrite – delicate, sometimes hidden flash

• Sunstone – sparkling golden flash (often called aventurescence)

In Summary:

Flash is one of the reasons people fall in love with crystals. It’s like a little secret hidden within the stone, waiting to reveal itself when the light, the angle, and the moment are just right.

So next time someone says, “Can you see the flash in that?” – take your time. Let the crystal catch the light. You might see something magical.

Photos above, 'Stones with Flash'. Top Left: Green Moonstone, Top right: Laradorite, bottom left: Anhydrite, Bottom right: Amazonite.