The successful culturing of abalone pearls has been known since French scientist Louis Boutan’s experimentation in the late 1890s, but commercial production has been achieved only in recent decades. The use of New Zealand’s Haliotis iris, with its colorful and iridescent nacre, has had the strongest recent impact on this industry. Empress Abalone Ltd. is producing large, attractive cultured blister pearls in H. iris. The first commercial harvest in 1997 yielded approximately 6,000 jewelry-quality cultured blister pearls, 9–20
mm in diameter, with vibrant blue, green, purple, and pink hues. Examination of 22 samples of this material by standard gemological and advanced testing methods revealed that the presence and thicknesses of the conchiolin layers had a significant impact on face-up appearance. Empress Abalone Ltd. is also experimenting with producing whole free-formed cultured pearls in this gastropod mollusk.