"Ben" wrote: That is probably not anhydrous borax. If it is a white fluffy powder, it isn't! You can turn your regular borax into anhydrous, but it will turn back overtime if exposed to the air. [Where I live now, I swear it might take only a few seconds:)]
As you heat it up, your regular borax turns into anhydrous borax as it melts. You MAY see two liquid stages. The first is where the borax dissolves in the moisture being driven out of the borax below it, then it will dry out and turn back to a white sludge, which will then melt. If you let this cool it will turn into a greenish glass. THis is what presently coats your crucible. If you grind this up into a grit or powder, you have anhydrous borax, which as harold says, will not blow away as easily as the plain stuff.
OTOH there is no need to waste your money on small jars of regular borax. THe 20 Mule team stuff in the box from the grocery or drug store, is the same stuff, at lower cost. [20 mule team borax that is, not any other product from them].