[2] The genus consists of small to very large, edible, herbivorous sea snails, marine gastropod molluscs.

The thick inner layer of the shell is composed of nacre, which in many species of abalone is highly iridescent, giving rise to a range of strong, changeable colors, which make the shells attractive to humans as decorative objects, in jewelry, and as a source of colorful mother-of-pearl.

[6] The iridescent nacre that lines the inside of the shell varies in color from silvery white, to pink, red and green-red, to deep blue, green to purple.

[7] These snails cling solidly with their broad muscular foot to rocky surfaces at sublittoral depths, although some species such as Haliotis cracherodii used to be common in the intertidal zone.

[citation needed] The shell of the abalone is exceptionally strong and is made of microscopic calcium carbonate tiles stacked like bricks.

When the abalone shell is struck, the tiles slide instead of shattering and the protein stretches to absorb the energy of the blow.

Material scientists around the world are studying this tiled structure for insight into stronger ceramic products such as body armor.

[10] The dust created by grinding and cutting abalone shell is dangerous; appropriate safeguards must be taken to protect people from inhaling these particles.

[citation needed][11][12] The number of species that are recognized within the genus Haliotis has fluctuated over time, and depends on the source that is consulted.

Those that have been reviewed tend to show that the abalone in general is declining in numbers, and will need protection throughout the globe.

Over half of the modern Haliotis species with sufficient data are considered threatened to some extent on the IUCN Red List, with all but one species from the Pacific coast of North America being critically endangered as a consequence of massive historical overharvesting, withering abalone syndrome, and recent marine heatwaves which have caused collapses of both abalone and their habitat.