Week 7: Galena

Do you know what kind of rock this is?

Why is it in this shape?

What is it used for? What can be made out of it?

galena

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Answers:

Do you know what kind of rock this is?

This artifact is an example of the mineral, galena. Galena is a lead sulfide mineral with a chemical composition of PbS. It is the world's primary ore of lead and is mined from a large number of deposits in many countries.

Rocks are not all the same. A rock is a solid, inorganic, naturally-formed substance without a particular atomic structure or chemical composition. It's probably easier to just remember that rocks are made up of two or more minerals.

Why is it in this shape?

Galena has a cubic crystal structure, which means that the cube shapes mirror the internal arrangement of the atoms. In other words, what its tiniest parts look like determine what it looks like as a whole.

What is it used for? What can be made out of it?

Most of the lead from galena is used in lead-acid batteries, such as those used in cars. Lead is also used for ammunition, television screens and computer monitors, oxides in glass and ceramics, and radiation shielding in the medical profession.