I need to buy a cat's eye gemstone?

Question

For gemology purpose, I have been asked to use a cat's eye. What should I look for as characteristics of a good stone? What things I need to keep in mind before I buy one and what is the approx cost per carat?

Answer 1

1) The type of gemstone: Cat's eyes are rarer and more valuable in some gemstone types than others, e.g. alexandrite vs. chrysoberyl

2) The prominence of the "eye": a stronger, more defined white stripe is better than a fuzzy or off-center one

3) Treatments!  MANY cat's eye gemstones are artificially enhanced through diffusion

4) Quality of the stone: a transparent, brightly colored stone is more valuable than a dull, opaque one.

The site below has pictures.