I need to make several neat holes in seashell (basically the main component is calcium carbonate CaCO3).
First idea was to simply drill, but it turned out to be too tough - two bits were broken with a very little progress.
The internet readily suggests thermal decomposition. But relatively high temperature is needed (circa 850°C) and also heat moves slowly in all directions, which isn't controllable.
Then was en Eureka-moment - simply burn through with electric current! But of course excitement lived short - in solid state it doesn't conduct electricity.
Therefore all my hopes rest upon chemical means only.
1. They say acids will do. But the only acids I can easily get hold of are acetic (ethanoic, CH3COOH) in form of a vinegar and citric C6H8O7. Both are weak and diluted. It seems, vinegar can be boiled for a while to increase acid's concentration. This may work, but again liquids react in all directions, so it's also not very well controllable.
2. Also I have an acetone ((CH3)2CO), and this may somehow work too. Not sure though.
3. Then for some reason I've thought about potassium permanganate (KMnO4), which is also readily available. It also should react, it seems. But of course I don't know for sure and how intensive reaction will be if any. In form of powder it's more controllable, which is great.
So, basically the question is: could you provide some insights, useful suggestions or perhaps some other ideas?
Thanks in advance.