Drilling holes in slate and granite

A pleasure sir. Doubt is like a pair of lead slippers, which we all occasionally find ourselves wearing. I had them on while tiling my 'undulating" walls.

"Stop smoking the weed, get a BIG cup of coffee gird thy loins, get some battens and a straight edge, and get plastering" was your advice to my cry for help. To the point, without being derogatory, it was this challenge that got my arse in gear.

I hope I have returned that feeling of confidence in you?

As it happens, today, I again used my diamond tile bit with great success and satisfaction. I used porcelain tiles on the floor in my new downstairs shower-room and they are extremely hard. I needed to drill 4 holes in them for securing the toilet pan. After trying a masonry bit first (not even a pinhole did this produce), I turned to my trusty diamond bit and (after holding the bit at 45=B0 to the tile surface, to make diamond contact porcelain, and start the cut) I had 4 perfect holes in about 8 mins.

I'm not (knowingly) familiar with quartzite, but if it's anything like porcelain, you'll breeze through it and your newly purchased bit will be lovingly stored in a prized place, within your 'tiling' toolkit.

:) deano.

Quartzite is somewhat between marble and limestone..in general feel. Nothing like as tough as granite, but more resistant to acid attack then calcium carbonate stones. Apparently its metamorphosed sandstone - i.e. a silicate.

Granite is silica alumina and potassium and sodium oxides..all good stable stuff, and all pretty hard.