Foil opal

Hey there kiddo! Have you ever heard of opals? They're these really pretty gemstones that can have a lot of different colors in them. Well, sometimes people make something called a "foil opal."

You know how sometimes when you look at something shiny, you can see your face or your hand in it? That's because it's reflecting what's around it. Foil opals are made by taking a thin piece of metal foil (like a very skinny piece of aluminum foil) and putting it behind the opal.

By doing this, the foil reflects the colors in the opal and makes them look even more bright and beautiful! It's kind of like shining a flashlight on a disco ball - the ball reflects the light and makes all these sparkly colors everywhere.

So, to sum it up - a foil opal is just a regular opal with a little piece of metal behind it to make it look extra pretty!