Home > categories > Minerals & Metallurgy > Vermiculite > perlite vs. vermiculite?
Question:

perlite vs. vermiculite?

I am teaching a children's art class and want to do a sculpture project with the kids. Some who have signed up are small and I am leary of giving them sharper tools to carve the plaster blocks I am making. I have instructions on mixing the plaster with vermiculite to make the plaster softer/slow down drying time. I have only found perlite- which is the same gardening-wise but I'm wondering if it will be the same for my purposes. I have found out vermiculite is clay based whereas perlite is rock I'm guessing I can experiment but figured I'd give a quick shout out first! Thanks!

Answer:

vermiculite is goldish colored...perlite is white I wouldn't dry them out in the oven; i'd compost it and buy new stuff... they are very inexpensive
Put it in the oven and dry it out. It is volcanic rock and there is no danger of any kind. If you heat it to at least 165 degrees for 30 minutes (at the coolest point) it will pasteurize the soil, meaning that at that temp any plant pathogenic fungi or bacteria will be killed. The issue with Vermiculite was asbestos occuring in some of the early mines. The dust created during mining was hazardous. This issue has been resolved.
Under NO circumstances do you put vermiculite into the oven! In the past there has been allegations of toxicities even being linked to cancers in laboratory animals. After all the product is quite inexpensive. (Not worth the health risk)
vermiculite and perlite are two different things, but I don't believe either one is toxic. Vermiculite is what happens when the mineral mica is heated, perlite is a naturaly occuring mineral of volcanic origin. However, if you dry it out in your oven, depending on how much of it you have, I would not have the oven over 150 degrees. And have adequate ventilation. It may take overnight, again depending on how much of it there is. Just keep stirring it occasionally, and keep checking to see how fast it is drying.

Share to: