[Rockhounds] concrete/cement

[jabac]

June Young wrote:
> I have a piece of jasper  that appears to have concrete/cement on it. ...

Do you know for certain that it was in concrete?

Often silica rocks from dry or desert environments are covered with
caliche, or various grades of common opal. It could be one of these and
will be difficult to remove chemically. In most cases a trip to the
grinder is required.


john