Faceting

amethyst rough before and after facetingFaceting gemstones embodies both art and science. Gemstone science includes optical properties of light, geometry of 3-dimensional shapes, and the physical chemistry of polishing gems and minerals. Gemstone art includes choosing the best cut for each stone and orienting stones to optimize beauty for each unique gem.

John is a gem cutter who works with all colored gemstones from Amethyst to Zircon.  He carefully studies each individual gemstone to determine how it should be cut to make the best finished gem in terms of appearance and value.

WORLD GEMSTONE DISTRIBUTION
AQUAMARINE Brazil, Russia, Afghanistan, Madagascar
CHRYSOBERYL Brazil, Russia, India, Sri Lanka
DIAMOND Brazil, Russia, Australia, Zaire, South Africa, Botswana
EMERALD Brazil, Pakistan, Zambia
GARNET Brazil, Russia, India, East Africa
OPAL Mexico, Australia, Czechoslovakia
PEARL Australia, China
PERIDOT United States, Egypt, Burma, China
RUBY Afghanistan, Burma, Thailand, East Africa
SAPPHIRE United States, Australia, Sri Lanka, Thailand
TOPAZ Brazil, Russia, Germany, Sri Lanka, Nigeria
TOURMALINE United States, Brazil, Italy, East Africa, Madagascar

These five are the most highly prized GEMSTONES
DIAMOND -- SAPPHIRE -- RUBY -- EMERALD -- PEARL

To be regarded as a GEMSTONE, a mineral must most-importantly be:

BEAUTIFUL in color

DURABLE to survive constant use without becoming scratched or damaged

RARE because scarcity gives it greater market value

The most frequent question I get from people returning from gem mining is “Are my gemstones worth cutting ?”

In general, I say there are three grades of rough gemstones: Facet Grade, Cabochon Grade, and Low Grade.

COMMON MISCONCEPTION ABOUT GEMSTONE ROUGH

“A beautiful high-grade gem is hidden inside my low-grade rough gemstone.”

Sorry to say, this is not true. There will not be better quality, or better color, on the inside of rough gemstones than the outside of the rough gemstone.

When facet-grade gemstones form, the outside surface is smooth and shiny with the appearance like glass. The inside will be the same "crystal clear" quality as the outside surfaces. What you see on the OUTSIDE of rough gemstones is the same as what is on the INSIDE of rough gemstones.

Low-grade rough gemstones can be cut. They typically will not polish well, meaning they will not be shiny. When I am ask about cutting low-grade rough stones, I advise not to cut them. But, I will as long as my client understands what to expect after they are finished. Dull and drab looking finished gems come from Low-Grade gemstone rough.

 

GRADES OF ROUGH GEMSTONES

Montana sapphire rough gemstones

FACET-GRADE ROUGH

Transparent rough gemstones with vivid or bright pleasing colors are best cut like diamonds, into faceted stones.

- Think about colored glass -

If  rough gemstones look like pieces of colored broken glass then they are likely high-grade rough gemstones.  And, candidates to be faceted into a finished faceted gemstones.

Ethiopian opal rough gemstones

CABOCHON-GRADE ROUGH

Translucent or Opaque rough gemstones with vivid or bright pleasing colors are best cut into cabochons.

- Think about smashed jelly beans -

If rough gemstones look like a colored jelly beans than they are most likely cabochon-grade rough gemstones. And, they are candidates to be cut into cabochons.

sapphire rough gemstones

LOW-GRADE ROUGH

Translucent or Opaque rough gemstones with dull or drab colors are best not cut at all.

- Think about gravel on a dirt road -

If rough gemstones look like gravel found on a dirt road then they are most likely low-grade rough gemstones. And, they would be candidates to be put on the bottom of a fish tank, or in a rock-garden. Even if low grade rough gemstones are cut, they will not sparkle or shine. I would not recommend cutting low grade rough gemstones.

  • I recommend faceting top quality Facet-Grade stones. Facet-Grade stones can be finished into fantastic looking sparkly gems.
  • I recommend making cabochons with medium quality Cabochon-Grade stones. Cabochon-Grade stones and be cut into very attractive shiny colorful gems.
  • I do not recommend cutting poor quality Low-Grade stones. Low-Grade stones can be cut into shapes and sizes that fit into jewelry mountings. But, they will not sparkle, or shine, or display vibrant colors.

From a handful of collected rough gems there may be one or two facet-grade stones, typically a few cabochon-grade stones, and a hole bunch of low-grade stones.  I can cut them all. However, I advise my clients to adjust their expectations accordingly.

The Holy City

I refer to the image on the face of this amethyst as The Holy City. I have heard this phenomenon called Pueblo Quartz. A good friend explained to me about Physical Chemistry which is the science of how gemstone crystals form. Well it's all a bit Greek to me. Whatever it's named or however it's formed, in all my years working with gemstones, this is by far the most interesting stone that I have seen.

I have handle tens of thousands of gemstones over the years. And, I have noticed something unique about quartz stones, usually as I polish facets.  As I polish facets on some quartz stones sometimes I notice patterns appear on the surface. Not every time. Not with every stone. But, occasionally, as my task light reflects off the surface, I notice a geometric pattern develops.  It reminds me of watching a photographic negative develop. I sit up a little straighter in my chair. I adjust my OptiVisor a bit. I move the light a tinge. All to focus more precisely on the polished surface. Very interesting geometric patterns show up on the polished faces. But then, I move-on, push-ahead, more stones to be cut. I finish polishing this stone and then I move on to the cut the next stone.

But, ONE DAY as I was looking closely at a few pieces of Amethyst rough stones, I noticed this truly amazing, natural, un-polished face on one of the stones. I affectionately call this Amethyst The Holy City.  Take a look. Be amazed. Let me know if you agree this is one of the most amazing things God made.

Facet Gallery