KNOB - Help please (Drilling Agate ) Sorted.

Tricky. If I were to try it, I would say buy a handfull of normal HSS drill bits and drill it out as slowly as you can with medium pressure, changing the drill bit as it goes blunt. No hammer action obviously, and don't press too hard that the bit bites too much materal and tries to rip bigger chunks out.
*I'm not an expert, and I have never done it before - just what would try myself.

Whatcha think Bruce ?

£3.00 bought it.

Quicker than the latex mould route.

Taken from a gem forum.....

After reading all the posts about drilling, I find I have some
important things to add. I did an article about this for Lapidary
Journal a few years ago.

First, your drilling process will improve a great deal if you add a
soluble oil to the water. There is a brand called Tool Cool that
works well. This will also save your bit.

Second, when you first start, the bit will cut well. When it begins
to slow down, as it will, it is because the diamonds have been worn.
If you're using smaller bits in the mm range, sharpen the diamonds and
clean the bit by running the tip of the bit over a grinding wheel,
preferably aluminum oxide while the bit is under water.

I use an old glass soap dish to hold the piece of stone in which also
has the oil and water, about 1/2 and 1/2. You should be able to tell
whether you're drilling throught the stone by a swirl of dust that
comes out of thie hole. If there is no swirl, try sharpening. Also,
once you're finished drilling, the solution can be left to separate
and reuse.

If you sharpen and it still doesn't cut, use a fresh bit.

Finally, don't be tempted to turn the piece over and try meeting the
holes from the other side. It won't work.

Good luck. the drilling takes much longer than you expect,
especially when \you think you ought to be through by now

Just bought 3x diamond drilling bits from a Hong Kong trader on Ebay for £3.50.

That should do the trick.

DOH ! misread the first bit , 2mm bit tight!!!! sorry