Ask-a-Geologist #20: What can you tell me about the mineral pyrite?

Today I have a special guest with me. Her name is Piper and we are discussing the mineral pyrite.  (Make sure you watch the video until the end to see our first blooper reel!)

Piper: I got this pyrite sample as a gift. Can you tell me about it?

The mineral name “pyrite” is comes from the Greek word for fire. People believe that pyrite got its name because it will spark when you hit it with a steel hammer.

Pyrite is a mineral that is most often known as “fool’s gold” because it looks like real gold. Do you know how to tell the difference?

Piper:  No. How do you tell them apart?

They are both gold in color and are shiny and have a metallic luster, which is what the mineral looks like in the light. One of the best ways to tell pyrite from real gold is hardness. Gold is soft – about a 2.5 to 3 on the mohs hardness scale, while pyrite is much harder, a 6 to 6.5 on the hardness scale. You can scratch gold with a copper penny but you can’t scratch pyrite. Pyrite is also lighter weight than gold.

Now you might have noticed that your sample of pyrite has some really neat features. You can see a bunch of little crystals all growing together. Pyrite forms natural cubes and octahedrons which are shapes with four and eight sides. Sometimes it can form crystals with 12 sides too. Sometimes, you can see lines on the flat sides of the crystals too. Do you have any more questions about pyrite?

Piper: What can I use it for?

Well, some companies use pyrite to make sulfuric acid, but you don’t need any of that. A beautiful sample like this is best in a collection like yours.

Remember to keep your questions coming in through the dig into geology section on our website or email us at    Please comment below and subscribe to our channel so that you get the next installment of ask a geologist.    Until next time, rock on everybody.

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