What kind of rock is it?

I've done it, rent a hammer drill from Home Depot or equivalent. I think I used a 5/8 bit. They will make you pay for excessive wear but that was not a problem. At the last of the hole it will break out,forming a basin, so you have 2 choices, drill from both sides and hope they hit, and that the drill doesn't wrap you up with it, or be concious of which side you want a neat hole in. Actually the break out is a nice effect, so I guess a few practice holes are in order. I only drilled Limestone and Sandstone,they are to the soft side, but I will need to drill a piece of granite soon.

That's great. I was hoping that you didn't need special equipment that wouldn't be available to rent or prohibitively expensive to do so.

Thanks,
jb

Also use water while drilling, it cools the bit and keeps the dust down.

Is this project a bad idea for someone like me who has limited experience with heavy power tools? My repertoire is pretty much limited to a regular power drill, hedge trimmers, small electric chainsaw, that kind of thing.

How long does it take? This rock I have in mind is basalt (what they call "columnar basalt" or "columbia column" at the rockery) and roughly cube shaped, about 14" on a side.

Thanks,

Kristin

Drilling through Basalt with a rented drill & bit from Home Depot may end up being an exercise in futility.
A top brand hammer drill & bit set may get through the Basalt eventually, but what you really need is a diamond core drill. This type of drill sends water down the center of a tube that has a ring of industrial diamond at the end. It will drill a very clean hole through the hardest of stones with minimal effort.

I'd suggest calling around to a few stone yards or stone fabrication shops in your area & see if they could do this for you.

practice on some old contrete first or stack up some cheap patio slabs to get used to the tool but when ready use lots and lots of water you will never have too much. have a friend with you to constantly hose the hole (a clever friend and if not a clever friend remind them about electrics and water not being good together)

a clever friend and if not a clever friend remind them about electrics and water not being good together

Hahahahahaaaaaaaaaa.

Stoneguy, I did call around -- the nearest place that does it is 2 hours away, and they want $100 just to set up and another $100 per linear foot of hole I want drilled. Bah!

Kristin