[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: calcium tablets

A reader previously wrote:

> >What about blackboard chalk pieces ?

Blackboard chalk was traditionally pure CaCO3.  Two or three years ago I
suggested chalk as a source for calcium and Paul Sears pointed out that
chalk these days isn't always CaCO3.  I checked what I had; it wasn't. 
Check yours before you try using it.  If it is CaCO3 then it should fizz
when hit with a drop of vinegar.

If you find some blackboard chalk that is CaCO3 then it should be a
useful source of calcium.

Roger Miller