Tiger eye or tiger's eye gemstones are popular. The distinct bands of iron oxide staining on a black stone gives it the unique look of a cat's eye, an effect called chatoyancy. A number of gemstones are chatoyant including true cat's eye which is a green-coloured chrysoberyl.

If the yellow-brown colour of tiger eye does not work for you, there is an attractive variant available called red tiger eye. The red colour is achieved through heat treatment (most gemstones on the market are heat treated including rubies and sapphires) which oxidises the iron, turning its colour to a reddish hue. I also have a less common yellow-bluish variant.

Tiger iron is an interesting gemstone from Australia which is a composite of three different gemstones - tiger eye, red jasper and black hematite. But the rarest type of tiger eye is the marra mamba also from Australia which contains several colours - reds, blues, yellows and greens! The Outback Mining website shows you some recent finds of this collector's item.

The Silverhawk Designer Gemstones website shows you drop dead gorgeous photos of finished marra mamba pieces that are absolutely to die for!

References
R.V. Dietrich. Gemrocks : Ornamental and Curio stones.