Chemical Formula: K(Mg, Fe3)(Al, Fe)Si3O10(OH, F)2

Color: Black to darker brown

Hardness: 2.5 – 3

Importance: The main use for biotite is as an insulator in circuits due to its low conductivity. Also used in paints and other industrial products.

Other Interesting Information: Always forms in very thin sheets, which makes it easy to identify. Has some elasticity, meaning it can bend to a certain degree without breaking.

My Take: Biotite is really cool. It is amazing that it forms in sheets that are almost paper thin. Only a few other minerals have this same trait.

For More Information


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s