Re: Yes, there is a Mineral Definition

"Carl 1 Lucky Texan" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> tabisheer is opal produced inside injured or diseased bamboo.
>
> What about chalcedony?

Chalcedony is cryptocrystalline quartz - so it is a mineral, but not a
mineral in it's own right - it's the same as quartz compositionally and
crystographically - just (very) fine grained with lots of pore space.
cheers
Bill