Hair Jewelry: A style of jewelry popular in the mid-19th century. Lockets of the hair of loved ones were preserved in brooches under glass. The hair was sometimes intricately curled or woven. These pieces were often inscribed on the back to identify the donors. Later in the century, hair was woven into watch chains, bracelets, and earrings and given as tokens of affection. All forms of hair jewelry are very collectible today.

Half-hoop: A bangle, bracelet, or ring in which only half of the circumference of the piece is set with stones.

Half-hoop design: An earring which resembles a ring but does not form a complete circle.

Hallmark: A form of consumer protection against fraud, hallmarks are simply marks stamped onto a precious metal by a legally appointed official after assaying to denote the amount of precious metal contained in a piece. European hallmarks are legally required and date back to the early middle ages. Marks are not officially required in the US but are carried by custom and practice. Marks may indicate the purity of the metal, the maker, the country of manufacture, and/or the date that the piece was assayed or had its design registered.

Hammered: A texture applied to the surface of an object with a hammer to give it a dimpled look.

Hardness: The measure of a stone’s ability to resist scratching, surface inclusions, abrasions or cracking. See Mohs scale.

Hardstone: The term used for any opaque stones used in making cameos, intaglios, or mosaics, such as agate, carnelian, onyx, etc.

Head: The prongs that secure a stone onto a setting.

Heart Cut: A "fancy cut" diamond or stone in the shape of a heart.

Heishi: (hee-shee). The oldest form of jewelry in New Mexico, pre-dating the introduction of metals. The literal meaning of heishi is "shell" and specifically refers to pieces of shell which have been drilled and ground into beads and then strung into necklaces. Centuries ago, the shells used by the Pueblo Indians to make beads were obtained in trade from the Gulf of California. The most commonly used are seashells of all kinds--dark and light olive shells, spiny oysters, mother of pearl, and melon shell. Coral and stones such as lapis, turquoise, jet, pipestone and serpentine are also used to create exquisite contemporary heishi necklaces. A string of good heishi will have a uniform consistency. If you gently pull it through your hand, it should feel like a single serpent-like piece. See Liquid silver and Olivelia Shells.

Heliotrope: See Bloodstone.

Hematite: Iron ore consisting of ferric oxide in crystalline form, hematite is silvery, shiny opaque stone that becomes a red powder when ground down. It manifests in splendent rhombohedral crystals that are very heavy and cold to the touch.

Hemp: Any plant of the Cannabis family. The fibrous skin is used for making cloth and rope. Hemp rope has become popular for necklaces, bracelets, and anklets. It is usually strung with brightly colored beads.

Herringbone Chain: A chain made up of short, flat, slanted parallel links with the direction of the slant alternating row by row resembling the spine of the herring.

Hessonite: A variety of garnet which is yellow in color. Also called "Cinnamon Stone".

Hidden box clasp: A box clasp hidden under the last link of chain so that when the chain is closed it looks uniform, except for the release lever.

High polish: A piece of jewelry that has been polished to a mirror-like finish.

Hoop Earring: An earring made from metal wire or tubing that has been shaped like a hoop. Charms and other ornaments are sometimes hung from the hoop.

Hopi Overlay: Jewelry made by Hopi Indians that employs a method of creating jewelry called the Overlay technique. See Overlay technique.

Hue: The specific color classification given to an object based on the seven colors found in the spectrum; red, orange yellow, green, blue, indigo, or violet. For example, garnets are found in a variety of shades of red from pink to plum, but all of these shades fall under the "hue" of "red". The more internally consistent a stone's hue is, the more valuable the stone is considered to be.

Hyacinth: A variety of Zircon used as a gem which can be brown, red, orange, or an amber-like combination of yellow/orange/brown.

Hydrous: Simply means "combined with water"; especially water of crystallization.