Abalone shell

I've had this Abalone shell for years - can't remember where I got it. This photo shows the iridescent inside surface (mother-of-pearl) of the shell.

"Abalone (from Spanish Abulón) are a group of shellfish (mollusks) in the family Haliotidae and the Haliotis genus. They are marine snails, and belong to the suborder Rhipidoglossa (in earlier classifications) in the large class Gastropoda. There is only one genus in the family Haliotidae, and about four to seven subgenera. The taxonomy of the family is still somewhat confused. The number of species recognized world-wide ranges from about 100 to 130 (due to the occurrence of hybrids).

Abalone shells have a low and open spiral structure, and are characterized by several respiratory holes in a row near the shell's outer edge. The innermost layer of the shell is composed of nacre or mother-of-pearl, which in many species is highly iridescent, giving rise to a range of strong and changeable colors which make them attractive to humans as a decorative object. The flesh of certain large abalones is considered by many to be a desirable food.

Abalones are also called ear-shells, haliotis, sea-ears and Venus's-ears, as well as muttonfish or muttonshells in Australia, ormer in Jersey and Guernsey, perlemoen in South Africa and pāua in New Zealand. They are dying out in Victoria (Australia) due to a virus leaking out of a fish farm in South Australia." From Wikipedia.