5/6/2008 · Among the softer gemstones, the cat's eye effect is often found in the gemstone apatite, in a golden color somewhat reminiscent of chrysoberyl.It can also be found in colorless, pink, yellow, green, blue and violet. But with a hardness of only 5 on the Mohs scale, cat's eye apatite is most suitable for pendants, brooches and earrings.