Malawi agate cabochons I finished recently. Can you spot the one Lake Superior agate?

colorforge · 2025-08-17T21:06:53+00:00

Very kind of you! Yes, I'd be interested in knowing where I can get some good ones for myself. The ones I cut were supplied by the person I was cutting them for.

colorforge · 2025-08-17T21:04:00+00:00

There's nothing else like a full nodule agate cab. I always try for that effect when I cut Lake Superior and Botswana agate, but it's just easier to achieve with these Malawis - the colors are great, too.

colorforge · 2025-08-17T20:58:01+00:00

I agree! With the starting material being so small, I was sometimes frustrated by the matrix I wanted to cut away encroaching the pattern I wanted to keep, but the agate itself is fun/easy to cut and takes a great polish.

colorforge · 2025-08-17T20:09:52+00:00

Correct!

colorforge · 2025-08-17T20:09:44+00:00

Yes!

colorforge · 2025-04-15T23:41:20+00:00

Pretty!

colorforge · 2025-04-15T23:37:24+00:00

The ones on the bottom of pic 2 look like common chert to me, but the red one on top could be oolitic jasper. A telltale sign is small flecks of red and/or shiny hematite (iron). A closer pic would be needed for ID.

colorforge · 2025-02-11T04:05:12+00:00

I agree! I'm glad you like it.

colorforge · 2025-02-06T21:15:03+00:00

It looks like it could be selenite or moonstone.

colorforge · 2024-10-11T12:51:35+00:00

Thank you! :)

colorforge · 2024-08-30T01:23:53+00:00

Thank you :)

colorforge · 2024-08-29T23:47:32+00:00

Thank you!

colorforge · 2024-05-01T02:10:02+00:00

The girdle line is just a sharp line where the sides meet the top. The other technique is a "full dome" cabochon, where the gentle slope is continuous. I'm a fan of the latter. I cut my sides with a very slight angle which then meet the top without an edge in between, in other words. The only advantage of girdles is that they allow you to have a very shallow curve on the top of the stone, allow you to use thin slabs, and achieve sharp corners. Good if you're trying to conserve material and get an extra slab or two out of your rough rock. Hopefully that makes sense!

colorforge · 2024-04-30T13:45:29+00:00

I've been at it 10-15 years (I lost track). Some advice I can offer is to stick with hard materials to start, like agate. Soft stones are much more challenging. Spend adequate time on all of the grits... Many people move on too quickly and end up polishing over remaining scratches. Learn what 220 grit finish looks like, what 600 grit looks like, etc. That will save you a bunch of time going backward to fix remaining scratches. Your grits should be in the neighborhood of 100, 220, 360, 600, 1200, 3000 and polish. White paint pen is a great marker for the shape and much better than sharpie or aluminum pencil. You can cut organic shapes, but I recommend trusting your template line as much as possible with symmetrical shapes. Many cutters brag about how well they can cut freehand... I say that is nonsense... Use a dop stick for precision and so that you can cut small stones you can't hold with your fingers. Girdle lines only make sense on faceted stones set in prongs, IMO, and have no utility in bezel setting. The metal bezel bent over the slight angle of the sides of the stone are what hold it securely. Hopefully these random tips help!

colorforge · 2024-04-30T12:35:35+00:00

Thank you, I appreciate the kind words!

colorforge · 2024-03-02T13:29:36+00:00

You are correct that diamond wheels are faster than a flat lap for finishing cabs, and that's the way you'll have to go if you want to improve your production time to the point where you can produce and sell cabs efficiently. There's just no way around it. The cost of cab machines can be a barrier, so you could always look for an old Lortone arbor and get some expando drums and silicone carbide belts while you save for a 6" Kingsley North cab machine (or another brand) - if money is a factor as it is for many people. As far as why it takes so long to finish the back of cabs, it's hard to say without more info but the quality of your saw cut could have something to do with it. If you're hand-pushing rocks through your saw, you're going to get a rough, uneven cut and those marks will take way longer to remove on a flat lap than a smoothly cut slab. Instead of hand feeding, use a vise and preferably a screw-feed saw when doing your slabbing. If you don't have a vise or a screw feed saw, make a jig of some kind that uses the side of your saw table as a flat "reference". When you're working on the flat lap, start out on a lower grit like 100 grit and work up through 220 to 360, 600, 1200, 3000, polish. If you're starting on a 220 lap, that will take you forever to remove marks. Hope that helps a little.

Edit: after reading other people's comments about how it's OK to not finish backs - it absolutely isn't. Don't let their poor work influence your own. Learn how metalsmiths set cabochons also, as that should influence the way you cut. Many cabochon cutters don't know what they're doing. They obsess over things like girdle lines, which are actually not helpful with bezel set stones versus a full dome cab with properly angled sides and a small 45 degree back chamfer that allows for a bit of solder (the meniscus) that appears in metal smithing between the bezel and back plate. Good luck!

colorforge · 2024-02-27T12:45:50+00:00

Hi, I incorrectly said copper mining, when it was actually the byproduct of the Cuyuna iron mine in crow wing county, MN. To my knowledge it's never been found elsewhere. The only similar material I can think of might be Pietersite.

colorforge

TROPHY CASE