Need help I.D. my Geode

[Ryan]

This geode has been in my family for over 25 years. My dad got it sometime in his travels with the Army. He was stationed in or performed some sort of army responsibilities in Oklahoma, Texas, California, and somewhere in Colorado as well as the carolinas. He is not sure where he found this stone but only remembers finding it and thinking "hmmm, this is a weird rock, it might be a geode." It then sat unopened in a drawer for much of the 70's.

Anyways, I have this vague reccollection of cracking it with a hammer in my garage as a very young child (1982-83?) and it has been mine ever since. (Wish I had a do-over on the hammer incident. This piece would look alot better if it were properly cut.) Im fairly sure it's smoky quartz inside but could use a keen eye to confirm this. Also I have no idea what the host rock is. I can only guess it's limestone from the looks but thats only a guess based on the fact geodes usually are limestone. As far as the location of origin, Im sure its impossible to determine based on a few pictures, but does anyone wanna throw in two-bits as to its composition? Or does anyone have one like this?

[lauriesrocks]

Looks like calcite crystals in limestone matrix.

[Ryan]

Thanks for the confirmation on the limestone laurie :-) As for the crystals, Calcite was a consideration of mine as well. Perhaps do geodes grow multiple minerals inside themselves? There are some 6-sided terminated points inside that I'm fairly certain are quartz but going back to look now, I see what might be lighter colored calcite crystal growth also. Im sure my crappy photography is far from definitive Maybe someday I'll make it to one of your roundups, which sound really fun btw, and I'll bring this guy. Thanks for the reply.

[scott]

you could always do an acid or hardness test on them. If you can easily scratch the crystal with a knife it is probably calcite (yes you can scratch quartz with a knife, but I'm mean relatively easy), and if you can afford to scratch a crystal enough to make a small amount of powder, add acid to the powder to see if it fizzes.

[lauriesrocks]

Yes you can have multiple mineral species in the same geode, such as quartz and calcite. For example many of the Brazillian amethyst geodes have calcite growing on the quartz.