Hopper To It!

Bismuth crystallizes in gorgeous crystals that have a hopper (like a grain hopper, see?) shape, so they're often just called hopper crystals.

...and they're really pretty...

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There are other substances that make hopper crystals, and they can be awfully pretty, but the iridescence of the Bi crystals is just something else...so pretty...

(KCl crystals - source)

Even when bismuth doesn't hopper, its crystals can still turn out to be pretty gorgeous.

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