After Dress, Jewels, Arms and Coat of Arms: Material Culture and Self-Representation in the Late Middle Ages, Central European University
“Goldsmiths worked mainly with the two most precious metals, gold and silver, and used enamel, pearls, and stones for the decoration of their products.
Gold was seen as the most prestigious metal, for which silver-gilt or silver were seen as poorer substitutes, most suitable for lower classes.
A large proportion of gold used in late medieval production was recycled gold: goldsmiths used ancient coins, jewelry, or other gold objects as their raw material. In the High Middle Ages, the previously produced gold stock of Europe was primarily accumulated in the court of the Byzantine emperors; consequently, little gold was circulated in the Western world. For coinage, for example, silver was generally used until the 13th century, when gold coinage was introduced in Italy, France, and England. This gold, however, was not newly produced but acquired through trade with the Arab countries, rich in gold since the early Middle Ages. From the fourteenth and fifteenth centuries, gold production in Europe increased alongside the continuing importation of gold from the Arab world. A significant quantity of gold was mined, especially in Bohemia and Hungary, which two countries provided up to eleven twelfth of the total gold production of late medieval Europe. Most gold was produced by mining, but some gold was also gained by panning (swirling the deposits of rivers around in a pan to separate quartz from gold), especially in the Rhine area.
Silver, in contrast to gold, was produced continuously through the Middle Ages in Europe, and even exported from there. In addition to silver mines that played an important part in silver production in the early and the High Middle Ages—Poitou (Merovingian period), Sardinia (11th-12th c.), the environs of Goslar, Germany (10th-12th c.), Freiberg, Saxony (12th-14th c.),—rich silver mines were discovered in the second half of the thirteenth century in Kuttenberg (Kutná Hora), Bohemia, which supplied silver in great quantities until its decline, due to the Hussite wars, in the fifteenth century.
Precious stones were acquired almost exclusively from long-distance trade. Among the most frequently used stones, rubies, sapphires, emeralds, turquoises, and diamonds came mainly from the East: rubies were brought from India and Ceylon, sapphires from Ceylon, Arabia, and Persia, emeralds from Egypt, turquoises from Persia and Tibet, and diamonds from India and Central Africa. Europe also produced a variety of gems and semi-precious stones in the later Middle Ages. The source for amethysts was Germany and Russia. Rock crystal came from Germany, Switzerland and France, opals and garnets, from Eastern Europe. Besides precious stones, also a great variety of less valuable stones were frequently used, as it turns out from a list of precious stones written by a Jewish merchant in 1453.
For precious stone decoration, goldsmiths very frequently used also antique cameos and intaglios — precious or semiprecious stones decorated with engravings or reliefs—that survived (often encased in older, medieval metalwork) in large numbers and were highly sought after in the later Middle Ages. Cameos were set into many types of jewelry as decoration, and often reused again. Their usage is a evidence of the conscious attempt to keep awake or revive the spirit of Antiquity. The popularity of antique cameos and intaglios was, in fact, so high, that medieval gem-cutting itself developed in emulation of the classical models. However, Western European Middle Ages knew only clumsy imitations of antique cameos, while in Byzantium stone-carving remained a living tradition throughout the Middle Ages. Byzantine carved stones were eagerly imported to the West.
Other raw materials for the decoration of jewelry included freshwater pearls from Scotland, mother-of-pearl, amber—the fossilised resin of pine trees—found in great quantities along the Baltic coast, jet—the black fossilised remains of trees—mainly from England and Spain, and coral from the Mediterranean coast in North Africa”.