Glossary – H

Half-Hoop Design

Also known as demi-hoop design, this earring looks like its name, forming only half a circle.
Hammered

A dimpled surface treatment created by a small hammer.
Hardness

See Mohs’ hardness scale.
Head

Head refers to the prongs that hold a stone in place on a setting.
Head Shape

The shape on the face of a ring is determined by the shape of the gemstone set in it.
Head Size Range

Head size range is the range of carat weight that a ring can mount in one specific head.
Heating

Heating is an ancient and normally stable enhancement that permanently transforms gems. Gemologists use low, medium and high temperatures in furnaces to alter gemstone color, clarity and phenomena. Nearly all of the world’s ruby, sapphire and tanzanite owe their color and clarity to heating. Many aquamarines are also heated to eliminate traces of green and gray. For a list of stone treatments, frequency and stability of treatments, and care instructions, visit our Gemstone Enhancements and Treatments chart.
Heishi

Literally meaning, “shell,” heishi (hee shee) is considered the most ancient jewelry form of New Mexico and is linked to the Santo Domingo and San Felipe Pueblo Indians. Heishi originally referred to pieces of shell exquisitely crafted and strung on necklaces. Now it may also refer to small hand-made beads of other materials.
Herringbone

A herringbone chain has small, slanted links that join to form a flat chain.
Hessonite

Hessonite is a brown red variety of garnet.
Hidden Box Clasp

This stylish design hides a box clasp under the last link of the chain.
High Polish

Mirror-like finish of a highly polished piece of jewelry.
Hoop Earring

This refers to an earring in the shape of a hoop.
Hue

Hue is one of three characteristics used to describe the appearance of color. Hue is the dominant wavelength of color attributed to a particular stone. (See also saturation and tone.)