Ok.. to get back on track:
You can synthesize metallic aluminum by electrolysis of aluminum ore, dissolved in molten chryolite, using carbon rod electrodes.
There are many aluminum ores in the game that dwarves don't know how to process. Given the absurd price for aluminum, our fortress could corner the market.
In addition, once cheap metallic aluminum is available, cheap aluminum oxide is also available.
While a handy abrasive, I was thinking more in lines of "genuine cultured sapphire and ruby".
Sapphire and ruby are both corundum. Eg, aluminum oxide. The difference is in which metallic oxide forms a replacement in the crystal lattice. Ruby has chromium oxide, which can be harvested from chromite. Sapphire contains iron oxide, which is easily sourced.
To produce the gems, you need clean hydrogen and oxygen gas. We have electricity, and carbon rod already since it is implied we are making aluminum, and that we have purpetual motion hydroelectric generators. We can get hydrogen and oxygen through electrolysis and compression. Efficiency isn't terribly important, given copious free energy.
The hydrogen and oxygen gas are carefully burned just on the surface of a boule of melted powder, which is very slowly lowered via a "puck". As the boule moves away from the flame, it crystallizes. As the flame is applied, new powder is sprinked on top of the boule to melt. This creates a long, thin ruby or sapphire. Depending on the size of the boule, you can slice it into wafers.
Sapphire (and pure corundum) can be used to fashion semiconductors, in small batches, if you have lasers. Ruby crystal can be coaxed into acting as a laser gain medium, if you know what you are doing.
(That in addition to cornering the ruby and sapphire market.)
Due to all this crazy that I have tucked away in my head, I suspect that the local true dwarves would be picking me apart after a few momentary lapses in keeping my yapp shut. Being fond of industry, ad knowing several industrial processes well enough to demonstrate them (sulfuric+boric acid annodization ftw! Multistep gold electroplate for added awesome, and synthentically prepared gemstones and mass production of aluminum metal, and I am sure a statue is in order.)
After this initial brain picking, I would retire from the limelight to make soap and the like, because it is relaxing and rewarding.... up until explosives get mentioned, then the mad scientist hat goes on again. Nitrocellulose, celluloid film (hollywood time!), nitroglycerine, napalm, and squibwires later, when dwarves are busy playing with flamethrowers and claymore antipersonel mines (and pornographic movies), I would get to relax in comfort again, unless somebody asked about poisons, and then the whole trainwreck happens again.
I would be "that guy" that everyone either loves or hates, because he seems to know everything, but really just wants to sit at home and do nothing with it, except make small handicrafts.
Think a male version of martha stewart, with added bombs and deadly poisons in the kitchen, and you have my basic persona.