The things that I consider when purchasing cabs are these:
Interesting material - color, pattern, durable
Cut thin enough to make jewelry - thick cabs don't work
Shape - not oval, asymetrical, graceful
Polish - perfect, no undercuts,
Back relieved on edge to accomodate solder fillet
For pairs - reasonable pattern and color match
Size - appropriate to the use - 1x2 inch rectangles are too big for earrings
Price appropriate to the use - I wouldn't buy a $100 stone to set in a silver pendant - you would have to get over $600 retail for the piece and that probably won't work often enough to try;
As to whether the stone or design makes the piece - it all works
together, but just setting a stone with nothing else very seldom
sells - it needs to show the hand of the designer. I often combine
unexpected color combinations - gaspiete and sugulite for example.
People especially like designs with names. Try and set some of your
cabs - you will quickly learn what works.
As to selling - get out there, sell and you will learn far more than
intellectual examination of the product and process.
In this day and age and competition - what seems to matter is that
jewelry is original, not mass produced, and unusual. Finish matters,
design matters, it needs to feel good, hang right, and pop - that
undefinable spark that identifies the work of an artist.
Good luck - we need more good lapidaries.
Judy Hoch - in rainy Denver - fall is coming.