Wednesday, July 29, 2009

Me and my Genie: Making Ordinary Rocks Pretty . . .

While trying to describe to someone how I polish a stone and what lapidary equipment I use, it occurred to me that I should maybe post a blog entry with photos. So here goes.

I don't cut my own slabs. Instead I hit the local gem and mineral shows, buy from ebay rock shops or trade with friends who, like me, periodically clean out their stash to make room for new stuff. I begin with a little slab of whatever material I want to polish - here it's prehnite because I LOVE the color and it's something I've only bought in finished cab form. Since I've not polished prehnite, I'm not familiar with its polishing habits so I'll enjoy a challenge.

Most really and truly lapidary folk have a trim saw to cut their little slabs into the desired shapes and they will cut their stones into either weird shapes to accent the stone's patterns for show displays or into calibrated sizes so that they fit pre-made bezels. Not a fan of calibrated cabs - pesonal preference. However, I'm lazy and I'm cheap and I used what my instructor called the Bowes-O-Matic Trim Saw: a ball peen hammer. Actually, in class I got tired of waiting my turn on the trim saw so I started breaking my slabs with bigger rocks. Anyhoo.

At this point, some people will glue their stone to a short section of dowel rod or even a nail with either Gel Super Glue or green dopping wax stuff. I don't - it's a step I can do without and I prefer to use my fingers.

On my Genie's coarsest grit diamond wheel (80 grit), I start grinding the edges into the shape I want. Occasionally, a stone is too "soft" and if I know it will flake or grind too quickly, I'll start with finer grit to slow down the shaping process. Here I'm taking the edges down to a triangular shape on the diamond 80. (Side note: my Genie has six grinding and polishing wheels: 80, 220, 280, 600, 1200 and 3000 plus two buffing pads that I rarely use.)

Once I have the stone in the general shape I have in mind, I cut a 45* angle edge to start the rounded top leaving a little flat side edge so that a bezel will sit upright at a 90* angle to the base. Personal preference - I like my cabs thicker. I also check the sides and top frequently by holding the stone up to eye level with my thumb so I can see that the top is rounding evenly and I
don't end up with a lop-sided top on the finished cab.

I continue to work the stone evenly by constantly moving it in different directions, switching sides, keeping the motion even and stopping frequently to hold the stone up to eye level for an "evenness" check. At this point, I turn the stone over to the backside and make a small 45* angle at what will be the base. This step will ensure that I have left enough room for a solder joint if and when this stone is bezel set. Back to the top - I keep working the stone until I'm satisfied that it is ready for final polish with no flat places. If I find flat spots, I go back to the previous wheel and work them out.
You can see in this pic above that the back of the stone still has some cutting wheel marks so it will have to be taken back to a coarser grit to polish those out. No one will ever see the back but I'll know it wasn't finished correctly so back to the wheel it will go. Although I feel that my final 3000 wheel is sufficient for my purposes, I do have two buffing pads that I can use for a high polish.

I know that there are a bazillion other lapidary people out there who are more detailed and scientific in their approach to rock polishing, shaping and beyond, but this is the process that works best for my stones and me. I can really get into a groove sometimes and lose myself in the grinding and polishing but the best part is ending up with some spectacular stones and having the satisfaction of creating a piece of jewelry from beginning to end.


Jill said...

Very interesting! How big is this Genie of yours? I assume you're not storing it in a lamp! Seriously, I'm curious how big this tool is.

Ashley said...

Lynn, that is so cool! I really liked seeing your technique. It sure would be cool to have your own supply of awesome cabs!

bella-bijoujewellery said...

I really enjoyed reading that! I would love to polish my own cabs, but working from a bench in the house I think that might just be too much noise and mess.
When I get my own little studio space in a garage or something though - oh I would love to try that!

Sunny Rising Leather said...

Just about to get into lapidary myself: your work is inspiring and excellent!!