[Intro]

Have you ever seen a pearl? Maybe you've seen one on an earring or a few of them lined up on a necklace.

Pearls are really pretty, and they belong to a group of materials called gemstones, like diamonds, rubies, and emeralds, that are used to make jewelry. Jewelry just like Squeaks' necklaces.

Pearls and other gemstones have a lot in common. They're shiny, usually hard to find, and people like to make things with them. But, pearls are extra special, because they are made very differently from a normal gemstone.

Most gemstones are made by changes that happen in the Earth. When a bit of rock gets very hot or the other rocks around it push down on it very hard, it can turn into a shiny gemstone, like a diamond or emerald.

(Squeaks squeaking)

Well Squeaks, pearls are different because they aren't made by changes in the Earth. Instead, they're made by an animal: an oyster. Oysters are creatures that live in the ocean. Their bodies are mostly one big muscle inside a shell, which they build themselves, just like a snail or a clam. While an oyster shell is normally clamped shut, sometimes it has to reach out of its shell to grab food. And, after it eats sometimes a little bit of food, or other leftover stuff, can get stuck inside of the shell.

Oysters have a very hard time getting little pieces like that out of their shells, and that little bit of leftover food can sometimes become really uncomfortable.

(Squeaks squeaking)

Yes, Squeaks. It is a lot like getting a rock stuck in your shoe, except you can't just take your shoe off to get it out.

Since it's not easy for oysters to get that little piece of food or dirt out of their shell, they try to make it a little less scratchy by coating it in something called nacre. That's the same stuff they use to build their shells! And, it's very strong and shiny.

There's something else about nacre that makes it great for protecting the oyster from something scratchy. Can you guess what it is?

(Squeaks squeaking)

That's right Squeaks! It's also very smooth. An oyster can coat a little bit of trapped food in lots of layers of nacre, slowly smoothing out any sharp edges or points. The little bit of food becomes smoother, rounder, and shinier. And, the oyster adds more layers until it doesn't hurt anymore. As it makes itself more comfortable, the oyster also creates something beautiful: a pearl!

Not all pearls are big, though, or even round. They come in all sorts of shapes, sizes, and colours. Pearls can be white, or pink, or blue, or purple, or even green!

Even though they're made differently from other gemstones, pearls are still pretty rare. 

(Squeaks squeaking)

Oh, they're rare because not every oyster will make pearls, Squeaks. If it doesn't get something stuck in its shell, it doesn't need to make one. In fact, most oysters never make a pearl at all. And, if an oyster does make a pearl, it can take years for the pearl to get big enough to be used for jewelry. They start out incredibly small, and it takes lots of layers of nacre for them to grow to a bigger size.

Best part of what makes pearls special: how uncommon they are. People have been diving into the ocean to look for pearls for an incredibly long time. They don't always find one, but, if they're lucky, they'll find some very pretty ones.

Some people even find pearls by accident while they're eating oysters. A few years ago, one woman found 50 tiny pearls in an oyster when she bit into it. Can you imagine?!

(Squeaks squeaking)

If you could make pearls like an oyster, what do you think they'd look like? And, do you have any questions about oysters or gemstones or anything at all? Ask a grown-up to help you leave a comment down below, or send us an email to kids@scishow.com. Thanks, and we'll see you next time here at the Fort!

[Outro]