As to a slab saw or trim saw, I would suggest looking at the new Highland Park company. I saw these saws at the Franklin show and was very impressed with the quality.  As to the old timer companies, you just cannot beat the service of Covington.

The most skin friendly oil that you can use is food grade mineral oil. Same as baby oil. I buy mine in 5 gal. buckets from industrial oil suppliers who I find in the yellow pages.  Buying several buckets they usually will deliver.  I am told that this same oil is available at Tractor Supply as an animal laxative.  The industrial oil that I buy goes by the name of white oil or technical white oil.  When I  don't want to filter it and reuse, my plants don't seem to mind at all.

As to RV anti freeze as a coolant, I have an engineer in my classes who uses it. If you go to Wal-Mart, he says that the Prestone Brand  has an additive which makes it better than the Wal Mart brand.

Some very special Biggs, for sure. Great job.

In my opinion, that EBAY machine is way over priced at $300.00.  Watch for estate sales, look for a nearby rock club and of course, Craig's list.  I have purchased six wheel machines for that price or less and you can get a new trim saw from Harbor Freight for around $50.00 and just add a new lapidary blade. The machine in that EBAY add is just too limited in what you can easily do and if you have to replace wheels, bearing and the blade you really have paid too much.  I tell my students to search for a machine in driving distance and go inspect what you are buying. No added cost for shipping and you can likely even try out what you are buying. I have seen more than once folks who purchased a Genie on EBAY then by the time they purchased wheels which would work and sometimes pumps or a capacitor they could have purchased a new machine.

Rock and roll is a good way to describe a good motion.  Think of not only your hands moving but also your shoulders. Another BIG mistake that many cab cutters do is have too long of a dop stick. I teach using very short sticks and to hold the stick very close to the stone. This not only gives you support of the stone but you can feel what is happening between the stone and the wheel.  Look at a long dop stick and compare it to a broom handle duck taped to the steering wheel of your car and you sitting in the back seat trying to drive down a hill controlling the car holding on to the tip of the long broom handle. You have little control. Short dop sticks folks.

When cutting cabochons using any kind of wheel the key is to never stop moving the stone.  A constant flowing motion from the time that your stone touches the wheel and NEVER stopping for even a second or two is the key. If you pause, you get facets on your stone. When you are ready to pull away from the wheel, pull quickly.

Is any of that wood opalized or all agate?

Don't forget the danger of a bracelet, necklace, tie or scarf being caught in the belt. Folks have been choked to death.  It is not just fingers at risk .

I still have memories of the night my high school friend and I drove 25 miles to a night time cabochon class at a parks and rec center. The instructor was demonstrating with one of the current machines at the time which was a B&I gem maker flat lap machine with an exposed belt leading to the motor. We had just started when a lady reached thru the belt to flip the switch to cut her machine off. I will never forget that sickening thud as her finger was caught in between the belt and the pulley. When the instructor was able to back up the belt, the lady's finger was hanging by a thread. It had cut clean thru the bone. If you have any saws of other machines in your shop which have exposed belts, PLEASE, stop and fabricate some kind of guard on them.

I suggest contacting Murray Simon, president of Charlotte Gem and Mineral club. He was close with Ron Gibbs and still is in contact with Ron's widow and perhaps the file of Ron's techniques can be uploaded to this site. Murray's contact info is on the club website.

I absolutely LOVE psilomelane even though my fingernails are black for a week. I have never seen any with red around it.  Is the red as messy as the black?

Stunning! It even has smoke at the top of the flames... Oh my.

Not knowing what the material is, a leather pad and cerium may not help but worth a try for sure. If you still have a dull stone and you have done all the steps properly up to the polishing stage you can likely brighten it a bit with some clear shoe polish which is a last resort. In my classes, I have found that the lack of a mirror polish is due to trying to rush the process on any of the earlier steps. I can assure you that if you do not have ALL of the scratches out and a proper dome by the time you finish 600, you can spend a hundred years on a polishing pad to little avail. Before trying my suggestion of leather pad and cerium, it would not hurt to start back at 600 and go thru each step very carefully and see what happens.

I have found that with some types of obsidian, diamond just will not give a mirror polish. An old timer told me to try a leather pad with cerium oxide and it works great.  Although very dated, Covington still  has a chart of polishes that have been used for generations before diamond with different stones. It is a good reference and free.