Here's why:

* Hardness: Talc has a Mohs hardness of 1, making it the softest mineral on the Mohs scale.

* Electrical Insulator: Talc is an excellent electrical insulator due to its layered structure and weak bonding between the layers. This prevents the flow of electrons.

While talc itself has a hardness of 1, some forms of talc might have a hardness closer to 2.5-3 when mixed with other minerals or impurities.

Let me know if you have any other questions!