Amphibole is a group of minerals, not a single mineral. However, the hardness of amphiboles on the Mohs scale generally ranges from 5 to 6.

Here's a breakdown:

* 5: This is the hardness of apatite, which is about the same as a steel knife blade. Some amphiboles, like actinolite and tremolite, fall within this range.

* 6: This is the hardness of orthoclase feldspar. Other amphiboles like hornblende and glaucophane might be around this level.

It's important to remember that hardness can vary slightly within the amphibole group depending on the specific mineral.