Gemstone Rough, Slabs, Grading, Fractures, and the Trials and Tribulations to the Final Cabochon

by georgeingraham on April 8, 2008

Purchasing quality gemstone in rough form can turn out to be a very disappointing experience. The results of my personal purchasing experiences had led me to believe that I might in fact be missing something that may all along have been common place in other lapidary shops. Other Cabbers must have a section of their shop dedicated strictly to salvage techniques for the rough they purchase online! A great portion of the rough I purchase is really quite beautiful in the pictures that go along with the descriptions of these various chunks of rough. When I receive them in the mail, they still appear to be excellent.

Then then the eye opening experience of slabbing begins to show the true condition. Once I stare at the pile of slabs just cut and realize that most of it is fractured to a point that it becomes apparent that it will be necessary to design the cabs around the layout of the fractures.

Not being sure if this was common place when purchasing rough, I began to wonder if it was going to be necessary to have things set up so as to be prepared to stabilize a great amount of rough in order to salvage it. Much of the material is really quite beautiful. Nice bright colors, or great looking dendritics, colorful flame mosses, and plumes. I began to be quite sure that others must be sharing in this experience and they have to be working on ways to salvage such beautiful material.

I threw my experiences and thoughts out to other more experienced Lapidaries for discussion. After learning from others their experiences and how they deal with fractured material resulting from a purchase of rough, I realized that it is part of the process. At least it is, as a rule, if we decide to purchase rough without having it in our hands first.

One thing that became apparent right away. A good Cabber will not sell cabs that have been treated to begin with.

I listened to comments like, “If any resin or glue is put on one of my stones I say so and that is VERY rare. I don’t know how many cutters cover up cracks and voids with glue and not say anything. If you are paying low prices for your rough and the deal seams to good to be true then it is.” From Seth who owns Griffin Custom Opal.

Comments like, “Working around the fractures is what i mainly do, i like to think i coin the term “natural freeform” when cutting this way. Becasue you have to let the pieces fall were they lie, and look for unqiue shapes, in combination of color/pattern that works.”, and “As you point out Toa ( TaoGem Gemstones ), online is a big componate as too were one can buy such material. But then you almost always fight a lossing battle with sellers who first dont really know lapidary, (they may know mining, or minerals), then simple market materials based on names for value and not grading the rough as it should be. Its very easy for sellers to do this and part of the hobby when one becomes invloved in selling rocks of any kind.” from Shain who owns Freeformcabs.

These are just a couple of comments that opened my eyes so that now it at least makes a lot more sense. Yes, buying rough online can more times than not result in experiencing poor quality and likely very fractured material.

Realizing too that most sellers of rough are in fact not even experienced cabbers any way. It is likely the extent of what they do may well be the blasting of the material from the earth. No wonder it is likely fractured!

For me, the learning experience has brought me to a point where I will likely not purchase gemstone material in rough form online. I will be patient and look around my surrounding area so that I can get my hands on it first. Maybe even buy from someone who also shares the desire to turn out nice cabs and understands the importance of dealing in quality material. Yes, it will likely be more expensive. I am way ok with that. Also it was a clear from the members on the forum that it is far better to purchase slabs if we are going to buy online. We have a much greater opportunity to really see what we are purchasing.

To read comments from these and other experienced lapidaries on this subject visit the thread on the subject within our lapidary forum.

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