Everyone has probably done this but I'm new and just did it for the first time. It's fun! I collected about 20lbs of flat, black and white, flecked rock from the Sierra Mtns at Lake Tahoe. I wanted them bad to lug 20 extra pounds around. I smuggled them home in my golf bag....on x-ray they look just like the metal heads of golf clubs. :)
serial32 just cabbaged onto about 30 lbs of slate/granite that we hydrohammered out of a foundation we dug last week.......it looks really cool in his tank, I'm scared to put it in my salt tank though
SW Ontario is littered with neat rocks and smaller stones left over from the glaciers...I'v collected some smaller from our field to put in my tank. We haul out the huge ones go in the yard as garden decorations.
most of my tank decor is natural... my gravel all came from the local gravel pit... pea gravel... i love it... all of my drift wood is also real... but 100% of my rock work is local... even the lace rock... i get it from rock pits... so it's not man made... the only thing that i've purchased are the slate tiles on a couple of tank's backrounds, the sand, and the hundreds of terra cotta pots...
geode {gee-ode}
it's a round or egg shaped rock that has a cavity inside full of crystals, ive sen em oink, purple, blueish and pure white and any where from baseball sized to one in Howe Caverns hre in NY on display that is about 3 feet tall and 2 feet wide - - im really not sure what causes them but i would assume it's a heat compression phenominon....im sure PK can school us, lol