Make a simple ring out of a regular rock found around your house.
Tools I used to make this ring.

Wet tile saw
Drill press
Diamond coated core bit
Flat lapidary machine

You will also need a rock.

Step 1: Shape Your Rock

Start by cutting 2 flat sides on either side of your rock. They need to be flat for the next step.

Step 2: Cutting the Finger Hole

Next we need to cut a hole in our rock which will be the finger hole in the ring. I use a 3/4" diamond coated core bit in my drill press. I also use a plastic container filled with water. I have the rock inside the container submerged under the water. Water cools the core bit and the rock while providing lubricant for the bit. Water also eliminates any dust. I hold a piece of scrap wood under the rock so I don't drill a hole in my plastic container.
Takes about 5 minutes to drill the hole. Don't force the bit, let the diamonds cut through the stone. Left the bit up out of the stone a few times while drilling the hole. It helps keep everything cool.
Once the hole is made you can pop out the stone plug from the core bit.

Step 3: More Cutting

Back to the tile saw. I used a black marker to draw a basic ring shape on the stone. Trim the excess material away with the wet tile saw. Take your time as the ring is more delicate now with the hole drilled in it.

Step 4: Start Grinding / Shaping

It's time to start shaping the stone ring. I use a flat lapidary machine that I built myself. It uses 6" diamond coated flat lapidary disks of different grits. Start with a course disk. I'm using an 80 grit disk. slowly shape the ring by grinding against the spinning disk. make sure your water drip is on to allow for cooling and dust control.

Step 5: The Ring Is Almost Finished

Continue to grind / shape the ring till you are happy with the shape. I have the finished ring next to a plastic coke bottle cap for size comparison. You can continue to polish your stone ring with finer lapidary disks to achieve a high shine or wear the ring as it is.
This is a truly unique ring and I'm sure will impress your friends.

Please vote for me in the ring contest here on instructables