The photos below are a comparison of a commercial stone on the left vs. one of my custom cut stones on the right. Note that I treated both stones equally when photographing them. Neither has been “touched up” and both were wiped off with alcohol prior to my taking the picture. Also, for comparison sake, I did the best I could to cut a 6mm x 8mm rhodolite garnet of comparable color to the commercial cut stone. The one thing that is unfair is that the commercial cut stone is a bit more included. It now resides in my fish tank. 🙂
In this photo, notice that there is light reflecting and sparkling in the stone on the right, and a large lighter colored area in the middle of the stone on the left. The commercial cut stone was cut at the wrong angles and light will just pass through this area which is often referred to as a “window” or a “fish eye” and the stone will appear dead inside. The stone on the right sparkles because the light can’t escape through the bottom of the stone. It bounces around inside and then back up through the top, often in different colors due to the phenomenon of “refraction” (notice the little blue spots).
Look at the polish on the surfaces of the stones. The one on the right is highly polished. This greatly benefits the brilliance of the stone. The stone on the left was probably never polished well, and then it was most likely thrown in a bucket or bag with other garnets of the same hardness, and microscopically scratched and pitted as the stones were repeatedly handled. Even if this stone were “flawless, it would look included or dirty upon close inspection. Another thing to watch for when looking at the polish of a stone are “striations” or parallel lines/streaks that are actually gouges in the surface of the stone.
Both the photo above and the one below demonstrate bad meet points where facets should touch each other but don’t. Look at the closer edge of the table on the commercial stone and you’ll see a facet, a line, then a facet. Those facets should touch each other.
Cutting for Weight?
The stone on the left, oddly enough, was actually cut for weight and the stone on the right was not. The arrow points to the culet (the point on the bottom of the stone), which was cut on too shallow of an angle, creating the “window” that you can see in the top photo. This stone should have been cut smaller so that the proper optical angle could have been achieved. The other way to cut a stone for weight is to have the entire bottom (pavilion) of the stone “belly cut, the extreme opposite of the commercial stone I’m showing here. What is really sad is that often commercial cutters will cut a really deep stone, then make that last set of crucial culet facets too shallow and still cut a window, even though there was plenty of material to work with. Also, they’ll cut the crown, (top of the stone,) super shallow so that they can make a bigger belly in the pavilion, and consequently a heavier stone.
This last photo is just another demonstration of good polishing vs. bad polishing. What is that saying? A picture is worth a thousand words!
About all a person can say about the commercial cut stone is “Yep, it’s a 6mm x 8mm faceted rhodolite garnet oval”
They’re all the same right????