Cleavage (crystal)

So you know how sometimes when you break something like a toy or a cookie, it doesn't always break evenly - sometimes it breaks in a really clean straight line? That's kind of like what happens with crystals when you cut them or break them.

Cleavage is how well a crystal is able to break in a straight line. Some crystals have really good cleavage, which means they're able to break in nice clean lines that are straight and smooth. Other crystals might not have very good cleavage, which means they'll break in a more jagged or uneven way.

Scientists and people who work with crystals really like it when crystals have good cleavage, because it makes them easier to work with and shape into things. It's kind of like trying to cut a sandwich - if the bread has good cleavage, it'll cut into nice, neat slices, but if the bread is all crumbly, it will be harder to make the slices look nice and even.

Overall, cleavage just refers to how well a crystal can break or be cut into neat, clean, and straight lines.