Abalone: A shell button most commonly recognized by its deep blue or green iridescence. Buttons carved in cameo style, gold-paint embellished or cut plain and polished. Pink and red abalone buttons can also be found. If your button has a smooth back it was probably made since 1900. Example at http://www.buttoncountry.com/Shell1.html
Acorn: Look for a metal shank added to the actual nut, which is probably varnished. Souvenir buttons - not used on clothing.
Agate: A variegated Chalcedony (crystal-like stone) is a member of the Quartz family that displays colors in circular bands. Buttons are disc-shaped and polished and have applied metal pin shanks. www.pinterest.com/pin/391039180128218302/
Alemite: Seldom found large overcoat composition buttons marked on back with "When You Button Up Your Overcoat, Remember Your Car" because the button was produced as a souvenir by the Alemite auto lubricant company.
Alloy: A mixture of two or more metals like Bronze (silver and copper), steel (composed mostly of iron), brass (copper and zinc). Brass is the most common alloy found in buttons.
Aluminum: Looks frosty gray, likely made from bauxite ore. Most of the ones found by collectors were made in this country. Scovill Mfg. Co made "chased" ones. (Chasing is a metalworking technique in which a malleable metal is ornamented or shaped by hammering from the reverse side to create a design in low relief.) W.E. Harkness made hand-stamped aluminum buttons in the 40's. www.buttoncountry.com/Metals1.html
Amber: Translucent yellow to brown colors from fossil resin; dome-shaped. Hard to find. Pin shanks or applied wire shanks.
Amethyst: Transparent pale violet to deep purple transparent quartz. Very hard to find.
Animal Designs: A popular subject for picture, story, livery and mythological buttons.
Antiquarians: Clear or opaque small, glass button with a U-shank, slightly flat back and faceted front. Considered some of the oldest buttons ever made. www.buttoncountry.com/CandCGlass1.html
Antler: Includes staghorn, which was carved highly decoratively in Europe, especially Germany where they were popular Victorian travel souvenirs. Today's antler buttons are sold for casual wear. The vintage, carved varieties are primarily sought by collectors
Architectural Designs: Buildings of all types including castles, ancient buildings and ruins on all types of materials.
Aristocrats: Incised designs filled and brushed with gold or silver on black glass buttons. Rare and hard to find. www.pinterest.com/pin/391039180128218507/
Arita Porcelein: Porcelein buttons from the town of Arita, Japan. Realistic shapes and self-shanks. www.pinterest.com/pin/391039180128218544/
Armed Forces Buttons: Made for the various branches of the armed forces of the U.S. Dating from about the 1700s to the present.
Art Nouveau: A style of buttons reflective of the period during the end of the 18th and beginning of the 19th centuries. Three main designs: nonpictural (ribbon-like lines), pictorial (flowery or stylized portraits of women or sinuous flowers), geometrics (Celtic-inspiration). www.pinterest.com/pin/391039180128218699/
Adventurine: A variety of quartz, which is often referred to as Goldstone, a glass originally made by the Murano glassworks. The quartz wasn't as bright and sturdy as the later manufactured goldstone. A button made of manufactured goldstone has wire shanks or holes for sewing. Goldstone is also used as inlays.