Santa Maria is the term used to describe a particularly fine quality of aquamarine with a deep and avidly sought blue color. The name comes from the Santa Maria mine in Ceará, Brazil. Brazilian aquamarines with other degrees of quality are known as "Espirito Sant," "Martha Rocha," "Fortaleza," and "Marambaia." Beautiful aquamarines known as "Santa-Maria-Africana" are found in Mozambique.

This name can lead the unwary astray: the word "sapphire" is derived from the Greek word for "blue." But sapphires, which belong to the corundum group, occur in every color of the rainbow. Sapphires can be green, yellow, pink, or brown, and each bears the name of its color as a cognomen. When a stone is described simply as a sapphire and without any additional modification, then one is typically referring to the blue variety of sapphire. The red member of the corundum family goes by the name "ruby" and the orange-colored member is called "padparaja." Sapphires rank among the most avidly sought gems. Stones with a deep, cornflower blue color are especially valuable. The most important sapphire deposits occur in Australia, Burma, Sri Lanka, and Thailand.

Sautoirs are very long necklaces that hang elegantly and sensually all the way to the waist. Measuring as much as 120 centimeters in length, sautoirs were particularly fashionable in the 18th and 19th centuries. Sautoirs are frequently made without clasps and often end in an ornamental pendant or tassel. In the past, the two ends of a sautoir were often pinned with a brooch to one's belt, to the shoulder of a garment, or to two different positions on a gown or dress. Other versions are fitted with concealed clasps so that the sautoir can also be worn as a multi-strand necklace or bracelet. The sautoir was Coco Chanel's favorite type of jewelry and is now sometimes also known as the "Chanel chain."

The Viennese mineralogist Friedrich Mohs (1773-1839) introduced the notion of "scratch hardness" as a way to classify minerals. He defined the concept as the resistance to scratching that a mineral exhibits when one attempts to scratch it with a sharp-edged object. Based on this attribute, Mohs developed his hardness scale, which is today's most commonly used system for comparing the hardness of gemstones. The Mohs' scale assigns each mineral to one of ten degrees of hardness. (See also The Mohs' scale of hardness.)

Precious stones typically embody the focal points of a piece of jewelry. During the long history of the goldsmith's art, jewelers have devised a variety of settings which hold the gem securely while simultaneously enabling it to optimally reveal its inherent color, light, and fire. Although the crafting of a setting is a task for a goldsmith, the actual insertion of a gem into its setting is performed by a specially trained craftsman known as a "setter." (See also prong setting and frame setting.)

Silver is a white, shiny, readily malleable and ductile metal. It has a number of superlative characteristics: for example, it is the most highly reflective of all metals and the best conductor of heat and electricity. Thanks to these attributes, silver isn't solely coveted for use in jewelry, but is also frequently used in chemical apparatuses, as well as in medical and electro-technical applications. The chemical symbol for silver is "Ag." This abbreviation is derived from silver's Latin name, "argentum." Pure silver is too soft for most applications, so it is usually alloyed with other metals. The phrase "sterling silver" describes an alloy in which 925 parts of pure silver are contained within every 1,000 parts of the alloy.

Like the reptile for which it is named, the snake chain is supple and flexible. Its surface is nearly closed because the flat links are shaped like scales that are very closely connected yet nonetheless entirely flexible. Snake chains are particularly well suited for use as chains that bear pendants.

The word "solitaire" is derived from the French language, in which it means "solitary," "alone," or "eremite." When used in the jewelry context, the term refers to a piece of jewelry which features a single, usually large diamond as its focal point. The term is often used exclusively to describe a ring in which a solitary, stately diamond is the undisputed focus of attention.

South Seas pearls are the finest and most precious of all pearls. Their size alone, which ranges between 10 and 20 mm in diameter, makes them particularly opulent. Pale South Seas pearls have a thick layer of nacre which may vary in color from white to silver, cream, gold, or even a pale bluish-gray. It is this nacre which gives them their gleaming luster. The largest and most beautiful South Seas pearls come from Australia. Indonesia is also an important producer. South Seas pearls grow inside bivalves of the species Pinctada maxima. The rarest and most costly South Seas pearls are white and almost perfectly spherical.

No two pearls are exactly identical. Even if they come from the same species of bivalve, there can still be tremendous differences in quality. In addition to the size, shape, color, and luster, another important criterion used to determine the value of a pearl is the nature of its surface. Uniform regularity is the most important criterion for the surface: the fewer ridges or indentations, the better the quality of the pearl. Pearls with perfectly immaculate surfaces are uncommonly rare because, after all, a pearl is a natural product.

Mankind imitates nature: a synthetic is a man-made mineral that has been created in a laboratory. Synthetics have the same chemical and physical properties as natural minerals. The first methods for manufacturing artificial stones were developed in the mid 19th century. The most common method is the melting-droplet process in which pulverized raw material is heated until it melts. The droplets falling from the molten material congeal into a pear-shaped body whose interior is identical with a natural crystal. Nowadays there's scarcely any precious stone which cannot be imitated. Man-made surrogates, however, must bear the additional designation "synthetic" when offered for sale.