Cat's-eye topaz is a genuine rarity: topaz containing fine parallel channels that gather light into a single bright line gliding across the dome of a cabochon. Combining topaz's hardness of 8 with chatoyancy makes these stones prized by phenomena collectors.GEMIC Institute maintains an unusually deep selection of cat's-eye topaz — every stone natural, certified by our Siem Reap laboratory, and filmed so you can watch the eye move on the exact gem for sale. Unique pieces; tracked worldwide shipping, 30-day returns.