Faceting

We Facet over 25,000 gemstones a year for Customers Just Like You who found Sapphires in our Sapphire Gravel

Faceting is a grinding and polishing process (commonly called “cutting”) that creates a beautifully finished gemstone suitable for jewelry. In addition to heat treating and faceting over 25,000 sapphires per year, we can facet your other precious and semi-precious gems. We regularly facet garnets, topaz, amethyst, citrine and sunstone. We have two options for faceting your rough stones. Our most popular option for small and average size sapphires and other precious and semi-precious stones is “Overseas” cutting. If you have a large, high value, sapphire, we recommend you spend the extra money to have your stone faceted locally in “Montana”.

Overseas Faceting

Our most popular option for creating beautifully finished gemstones from your rough stones is our “Overseas” cutting option. We undertake all of the sorting and grading and evaluate each stone individually to select the best cut to maximize the value of the gemstone. Each order is handled and packaged individually. We then ship the stones to Sri Lanka for faceting. Sri Lanka has a long history of producing gemstones and an excellent lapidary industry. Their government regulations and Customs strictly control the import and export of gemstones. Our detailed inventory sheets contain individual stone weights, piece counts, parcel weights and scanned color images of every order and are double checked to ensure you get your exact same gemstone back. Although Sri Lanka is not the least expensive locality to have the gemstones cut, our experience has shown that they offer the best cutting quality, especially the finished polish quality. Overseas cutting is the best option for small and average sized sapphires and other stones such as garnet, amethyst, topaz and sunstone. The cost of overseas faceting is very cost effective, we provide quantity price breaks making it cost effective to facet even small stones. As always, our services come with our full replacement and refund guarantee on our sapphires.

Montana Faceting

If you have a large, high value, sapphire, we recommend you keep you sapphire local for faceting in “Montana”. We consider any sapphire over three carats in the rough to be a “money” stone. A three carat rough stone will frequently finish into a one carat finished gemstone. Most of our one carat finished gemstones are valued at $600 to $2,000 each! Larger rough sapphires finish into even larger gemstones. We’ve returned sapphire gemstones to customers that we conservatively valued at over $20,000! As such, it’s worth spending the extra money for Montana Faceting.  We specialize in “specialty cuts”. We offer custom designs, special shapes and way more than just your standard 57 facet round brilliant. If you have a deep stone with a fairly light color saturation, we are going to suggest a three, four or five row Portuguese Round with up to 161 scintillating facets. If your stone is a little flat with a much larger diameter to depth, we’ll recommend an 81 facet “Sherry” cut with slightly shallower angles on the pavilion If you want an unusual shape, we have a custom “Square Brilliant” that will knock your eyes out. Yes, you can still get that standard 57 facet round brilliant for a little less money, but when you have a truly spectacular stone potentially worth thousands of dollars, we encourage you to spend the extra money and make the stone all your own with a custom cut of exceptional quality.

 Because we have so many options for Montana faceting, we break our billing down into two parts. You pay for heat treating the stone up front based upon its weight. We then re-evaluate the stone after heat treating to come up with ideas for the optimum cut based upon the color saturation, any zoning that may be present and shape of the rough stone. We will frequently mail the stone to one of our cutters for an independent opinion. The actual cost of faceting the stone is not calculated until the gemstone is finished. You pay based upon the finished weight of the gemstone and the number of facets. It takes much longer to facet a large stone with multiple facets than it does to facet a small 57 facet round brilliant.  

Cutting Yield

There is a big difference between size and weight. Many of our new customers are surprised when their cut gemstones only weigh a fraction of the rough stones they left. That is because there is a big difference between size and weight in relationship to shape. Most of the cut gemstones we return to customers are only one millimeter smaller in diameter than the rough stone, and we seldom lose more than two millimeters in size. However, the shape of a finished gemstone is markedly different than the shape of the rough stone. Most of our rough stones are relatively round and have a weight that can be calculated based upon the shape of a sphere (ball). The volume (or weight) of a sphere is a 4/3rds radius cubed function. However, a cut gemstone has a flat top and a pointed bottom. It is a cone. The volume (or weight) of a cone shape is a 1/3rd radius squared times the height function. Simply because of the change in shape from a sphere to a cone, there is a 4/3 to 1/3 loss in weight ratio which is compounded by a radius cubed loss due to any loss in diameter.

 The weight of the finished gemstone verses the weight of the rough stone is referred to as “yield”. The yield of the finished gemstone is totally dependent upon the shape and size of the rough stone. Irregular shapes and smaller sizes have a much lower yield. The average yield of 3 and 3.5 millimeter cut stones is only 18%. When we are cutting very small 2 mm and smaller accent stones for our own use in building jewelry for the store the yield is only 6% to 9%. As the rough stones get larger, the yield increases. We usually get 25% yield from 1.5 to 2 carat rough stones. Two carat and larger rough stones typically yield finished gemstones that weigh 25% to 33% the weight of the rough stone. It is very rare to have a finished gemstone weigh more than 35% the weight of the rough stone. Again, the finished weight of the gemstone is totally dependent upon the shape of the rough stone.

In general, we only lose one to two millimeters in size, but the average weight of our overseas cut stones is only about one-fifth (20%) the weight of the rough stone. The actual finished weight of a gemstone is dictated by the size and shape of the rough stone, and the finished gemstone weight will vary from 6% to 35% of the rough stone weight.