Going broke for sure. But I think the potential for electric shock may rank right up there.
We work with our hands wet around electrically-powered machines. Most commercial units are designed with shock protection in mind but it's something to think about when doing work with home-brewed designs and unusual equipment arrangements for drilling, carving etc.
There are others here that know more about electrical hazards than me and I hope they'll chime in with their knowledge/experience.
Eye protection is another biggie for me. I got a small rock chunk in my eye while grinding a cab some years back. It caused a lot of problems and pain. I've also had small rotary disks explode while using my Foredom for metal work. The most dangerous IMO are the little silicon carbide disks that can be very handy for certain jobs but are fragile and easy to misalign leading to little pieces flying everywhere.
Fuel gas and oxygen connections are another concern. They should be checked fairly often with soapy water to ensure against leaks. Propane tanks used indoors can be dangerous because propane is heavier than air and accumulates near the floor unless ventilated. Overfilled tanks will vent during hot weather so safety people recommend that tanks be kept outside with the gas piped to the work area.
Indeed Electrical hazards are real. Some lapidary equipment is VERY old. I'm currently restoring a VERY old 20" saw. The electrical was not working when I got it. The wiring I removed was old fabric insulated wire. The insulation was broken down in several spots. This machine had been upgraded a couple times but that old wiring was still in use.
Be sure your equipment is properly grounded. If you get hooked up with 120V from a shorted motor, It could really ruin your widow's/widower's day.
Be sure you have GFCI protection for your equipment. Individual GFCI unit can be purchased to plug into your outlets or if you are capable you can install GFCI outlets.
BELT GUARDS! Why do most old pieces of lapidary equipment not have belt guards? Man! I've seen fingers that have run through a pulley! UGLY! For your sake and the sake of your friends, family and visitors, PUT BELT GUARDS ON YOUR EQUIPMENT! (Google images of fingers caught in pulleys. It will make your toes curl.)
Keep all of all your fingers. Some of us work with more dangerous tools, like table saws or circular saws or metal shears. I once worked with an old Englishman. Aubrey had been a machinist for 40 years and still had all of all his fingers. His advice to me? When you approach a machine that can potentially hurt you, STOP.... count your fingers and be sure you have all of all of them before you start and that awareness will help you have all of all of them when you are finished.
Rocks and rock equipment are HEAVY! Be careful how your lift and move heavy stuff. If you can't walk because you messed up your back, you can't play with rocks!
If you drop that beautiful 15 pound Brazilian agate on your toes, you will be hobbling for a while. That 15 pound rock is moving about 11 mph after falling 4 feet. That is over 81 joules of energy or about 58 foot pounds of force smashing your toes at 11 miles per hour. Broken toes will make you limp for weeks and it makes rockhounding much more difficult.
Don't let routine cause you to not be safe. " I've done it this way hundreds of times" But on the 101st time something goes wrong and your finger gets sucked in between a grinding stone and a tool rest. Make being safe a routine. Safe is much better than hurt!