Obsidian Carved for thousands of years, and in nearly every culture of the world, this volcanic glass has been converted into mirrors, daggers, swords, plates, and ornaments of every sort. For its use at war, the stone still bears an aggressive symbolism in Mesoamerican cultures. Its imposing, mysterious black has, perhaps, also made it an amulet of protection.

Moonstone The ancient Romans believed that moonstone actually captured the rays of the moon inside itself. Thus the name and its use in ornaments. It’s also associated, in both the Greek and Latin cultures with female lunar deities. It’s been used as a deeply feminine stone, for communicating with the gods and as a companion in divinatory rites.

 Jade Jade’s intense color makes it one of the most used stones in the creation of jewelry. The etymology of the name (ilia, “bowels” in Latin) relates it to the intestines, and it had been used to treat evils in these organs. In addition, jade was used for ceremonial and decorative purposes in the Chinese, Indian, Olmec and Mayan civilizations. It’s currently used as an amulet to attract good fortune, prosperity, and abundance.

 Turquoise Extremely valuable for its rarity and beautiful color, the name comes from Turkey, the place through which it first arrived in Europe, during ancient times. For their part, the Aztecs called it chalchihuitl, a word that might be translated as “the one who’s been pierced” (again, as it was often used in jewelry). In more modern times, turquoise is used by clairvoyants and in divinatory rituals.

  Amethyst A purple-toned quartz, amethyst is used as a protective amulet, and it fosters meditation. The name is the result of a Greek myth: Dionysius, the god of wine and debauchery, fell in love with a maiden named Amethystos, who wished to remain chaste. To help her, the goddess, Artemis, transformed her into a white stone. Dionysius, now humbled, poured wine onto the stone and it took on the purple color it bears to this day.

  Sapphire A stone of intuition and communication with the spiritual world, sapphire’s rarity, and deep blue coloring (although there are also yellow, pink and orange sapphires) and spectacular brilliance make it one of the most valuable stones in the world. It is the gem for the month of September and was associated, in the ancient Latin world, with the planet Saturn.

   Ruby A stone of love and courage, and an aphrodisiac par excellence, the presence of iron and chromium in this valuable stone provide its hypnotizing red color (it’s also the product of a chemical oxidation process). It’s no accident that the name of the mineral comes from the Latin ruber, meaning simply “red.” In some Asian cultures, rubies were used to decorate armor, the sheaths of swords, and they were sometimes placed in the foundations of buildings to ensure future endurance.

 Opal One of the most beautiful of stones (classified as mineraloid, because it’s non-crystaline) opal’s beauty nevertheless arises from the litmus of colors it bears, each generated by its ability to diffract light. The name, according to some experts, refers to Ops, a wife of Saturn and a goddess of fertility in Greek mythology.

  Emerald In color, the emerald ranges from yellowish green to bluish green, and it’s considered the stone of intuition, love, and abundance. The emerald is one of the most valuable and revered of gems. According to legend, after his trips to the Americas, Hernan Cortes returned to Europe with a great number of emeralds.

  Diamond The diamond, perhaps the most valuable of stones, and certainly the hardest, also has the most beautiful name. Our word “adamant,” comes from the Latin meaning “unbreakable,” “incorruptible,” and “unconquerable.” In the Middle Ages, diamonds were considered the tears of the gods, and for this reason, they were used as amulets of good fortune during war.