H

half-drilled pearls

pearls drilled to 2/3 or 3/4 of their diameter for setting in pearl jewelry.

half-round nucleus

nucleus used to produce cultured blister pearls

hama-age

 newly harvested cultured akoya pearls in Japan

hama-age auctions

 annual auctions of newly harvested cultured akoya pearls in Japan

hanadama

highest quality portion of a cultured akoya pearl harvest; often used for rings or earrings

hardness

 pearls range from 3.5 to 4.5 on the Mohs hardness scale

harvest

removing cultured pearls from mollusks on a pearl farm

hue

first impression of a pearl’s color

hypostracum

 mother-of-pearl layer of a pearl-bearing bivalve mollusk shell, the shell layer adjacent to the mantle

Hyriopsis cumingi

a triangle shell mussel native to China, being used extensively in cultured freshwater pearl production

Hyriopsis schlegeli

a Biwa pearly mussel native to Japan used to produce tissue-cultured freshwater pearls in Lake Biwa