is Soapstone Safe for a freshwater aquarium?

Factual Questions
1

I have a beautiful chunk of soapstone that would look great in my aquarium. I need to know, before I plunge it in, is it safe?
It is a freshwater aquarium that runs at about 7.0 - 7.4 pH, 40 gallon with mostly tetras, gouriamis and a few bottom feeders and a nice assortment of real plants.

Any one got any experience with soapstone in an aquarium?

2

From my days working at an aquarium -
Soapstone:
Give it a quick rinse in warm water. Then dip it in vinegar. If the soap stone sizzles and produces small bubbles in the vinegar, then it is not safe for aquarium use. If it doesn’t go ahead. Be careful though, soapstone if pretty delicate and will eventually wear away in aquariums.

3

I wouldnt use it. I think its mostly talc and that will definately dissolve in the water. I dont know if talc is an acid or a base, but it will change your water chemistry.