On Sun, 23 Dec 2018 21:18:58 -0600, dpb wrote:

On 12/23/2018 6:44 PM, Ian Metelly wrote:
Can you help me identify some insulation? I hope it's rock wool and not
asbestos. ...

I agree w/ the others--it's rock wool. Either, way, wear protective
gear and don't go out of your way to raise dust and no problems...

Knowing the age of the house will narrow it down.

To me, it looked like blown in cellulose insulation. That's my rulin'.