Mace or True mace is the dried, ground outer shell or whole flakes of the kernel of the fruits of the beautiful evergreen nutmeg tree (Myristica fragrans Houttyn). The nutmeg fruits resemble small peaches. When ripe, these luscious tropical fruits split open to reveal one of nature's most handsome combination of colors. The first layer or cover is a vivid green, the next a bright orange, and the third layer is the brilliant scarlet aril which protects the nutmeg kernel. This is the covering which is dried and ground to produce the spice called mace. It requires more than 400 pounds of nutmeg kernels to supply enough coverings to make 1 pound of mace. Like the other spices, all maces take their particular name from the districts from which they originate and are exported. So we have Amboyna mace, Banda mace, Granada mace, and Penang mace among the true maces. Mace, like nutmeg, is used in comination with cinnamon, cloves, allspice, and ginger, as well as alone. The flavor is much stronger than that of nutmeg and the other spices; and when used in combinations, the proportion of it should be considerably less. Many formulas for blended ground spices include maces. Spices such as the poultry seasonings, prepared meat and sausage seasonings used by the meat packers, prepared mustard sauces, Worcestershire sauce, Yorkshire relish, and Cambridge sausage all contain aromatic golden grains of mace.

Source: Miloradovich, Milo (1950). Cooking with Herbs and Spices. New York: Dover; pp. 231-232.