One of the three primary factors of value in gemstones, and the only one that depends on
the facetors judgement and skill.

Why is an American cut stone worth more than a native cut stone, assuming the clarity and
color of the rough were equal.

A function of economics.
Native cutters get paid by the day, and the wholesalers sell parcel lots by weight.
So getting a little extra weight on a stone by cutting the pavilion to the maximum they
can get out of the rough, increases the wholesalers return for investment.
Thats why pearls always have the hole to small too, more weight.

American cutters sell individual stones, and get much more for one with extreme brilliance,
Cut correctly for the optical effect.

Considering that the faceting instructions usually are given for quartz, as this is 
the material recommended for practice cutting, so to cut other stones, you need to 
covert the mathmatics. Some books only give the angles for the mains, and you have to 
deduce or use a formulae to get the angles for the stars and break facets.

Other mistakes to watch for.
Crown, Table not symetrical, or lobsided on the stone.
stars not the same height.
Points on facets running beyond, or not meeting the girdle or table.
Stair stepping on the girdle facets.
Poor polish or scratches.
Pavilion, to deep or to shallow. 
Culet off center.
Main facets not symetrical or wrong angle for the material.
Appearance-- dullness, bowtie black areas, dark table.
And of course fractures and inclusions.
In some stones inclusions are a positive.

Rutilated quartz, schiller in sunstone, jardon in emeralds, and
moss agates.

Considering facet rough of high quality is rare, 
and how cheap native cut stones can be purchased for.
An American hobby facetor could purchase native cut stones,
and recut to a smaller size and make a pretty good profit.
Assuming they had a market outlet.

FACET DESIGNS

homepage