Valuable Rough Gemstones

I have heard some people complain about the cost of rough gemstones. Before you complain there are a few things you should think about.

Well the first question that you should ask when you see a piece of rough is.

What can I make on this piece of rough when I cut it?

Here is an example using a very nice piece of rough Aquamarine I had for sale.

Item #: Large Aquamarine Crystal – $12/carat (2001)
Locality: Pakistan
Aquamarine Crystal/valuable rough  Aquamarine Crystal

I very seldom see Aquamarine crystal of this quality and size. This is good solid medium color blue and other than the growth line and little spot next to it, clean. The will cut some very large, quality stones.

1 each 186.0 carats – $2,232.00 – blue/blue/green, best cut Barions – 26.5mm x 54.8mm x 11.2mm deep

Does the $2,232.00 give you sticker shock?

Well it may but it should not. Here is why.

First thing to do is inspect the rough and see what quality it is and what it will yield. On this piece, it is quite good quality and will yield very high and in about any shape(s) you want.

So this piece of rough costs $2,232.00, it weighs 186.0 carats… and that works out to a rough per carat cost of $12/carat rough.

This translates into a $60/gram cost for the rough. With a yield of 30% (this is conservative, I think) the rough stone will yield 55.80 carats of very nice quality clean Aquamarine gemstones.

So $2232.00 divided by 55.80 finished carats = $40/carat actual cost in the finished gemstones. Not counting any wear and tear on your laps, but lap wear is not that large of a factor unless you are very hard on laps.

Now ask yourself, what would these large clean finished Aquamarines sell for? This crystal will yield stones in the 10 to 30 carat range (probably 15-20 carats is what I would shoot for), maybe larger or smaller depending on what you cut.

Larger stones always bring a higher prices, especially matched sets, and clean… But let’s assume for argument sake that they will bring $80/ct wholesale, which is a real bargain.

So basically you just doubled your money… and that is wholesale, retail is a lot more. $80/ct times a yield of 55.80 finished carats = $4464.00

Still have think this rough is expensive? Not hardly. Always ask yourself…

What can I make on that rough? Do not worry about what the other guy is making. Worry about what you are making.

Here is an article on how I would cut this crystal.

How do I get the best yield from a crystal? How do I figure it out?

Do the math before you assume something is expensive, you may be surprised.

About the author
Jeff R. Graham
The late Jeff Graham was a prolific faceter, creator of many original faceting designs, and the author of several highly-regarded instructional faceting books such as Gram Faceting Designs.
All articles by this author