In this post, I want to talk about glass and paste stones.
There probably isn’t a gemstone that glass has not been used to imitate, including all the precious gems but also including turquoise, jade, opals, jet, amber, tortoiseshell, agates, pearls and so on. Glass has been used in jewellery for centuries, with examples found dating from 1500AD. It was so popular as a gem imitant in the 11th century, that the guild of goldsmiths in France was required to regulate the use of glass in jewellery. Their approach to do was to use gold for natural gems, silver for glass gems.
Murano, in Italy, has been a centre of glass making since about 100AD and had a reputation for exporting imitation gems. In a decree in 1487, the Senate of Venice forbade the making of imitation diamond, rubies, spinels, emeralds, sapphires, and amethysts. In 1644, there is a record of goldstone being made in Murano. Goldstone is meant to be a replica of aventurine quartz, a lovely stone with mineral inclusions which look like flecks of gold.
Jewellery found on the body of Edward I of England was found to contain glass, and jewels belonging to Richard II of England contained glass. Elizabeth I owned glass jewellery, as did Mary, Queen of Scots and Queen Anne, wife of James I.
Up until the 17th century, glass was molded and lacked the sparkle of real gemstones. Rock crystals, which had had a higher dispersion, was often used to duplicate gems in preference to glass because it could be polished and faceted to some extent. However, in 1675, flint glass which has a high lead content, was developed in the UK by George Ravenscroft. It had high dispersion and higher refractive index than molded glass or rock crystal. The real breakthrough for glass to be used in jewellery was when, in 1724, French jewel designer Georges Frédéric Strass came up with ‘paste’, a leaded glass that he cut and polished with metal powder until it shone like a diamond. Named white ‘diamante’ or ‘strass’, the stones became very popular in Parisian high society. This was at a time, when the use of wax candles in the evenings led to more social events being held at night and people wanted to be seen to be wearing sparkly gems. Paste stones, in a range of different colours, remained popular and acceptable in the 18th and 19th centuries. In 1840, a process to permanently foil pastes was discovered.
Many 18th century paste stones had a small spot of black paint on the culet. It was said to be used to simulate the dark spot seen on the culet on a brilliant cut diamond.
Other types of glass gems were made. In 1763, James Tassie, a Scottish gem engraver, developed vitreous glass panels which were used for cameos. They were known as ‘tassie’ cameos.A merchant in England developed opaline paste, which was a milky paste set over rose coloured foil, imitating opals. Vauxhall glass was made by a mirror glassworks in Vauxhall, London. This was glass that was faceted, then applied to a metal background which was then pained black. It was used to imitate jet. Another glass imitant of jet was French jet, which was hard and glittery, and colder to the touch than jet.
Toward the end of the 19th century, Daniel Swarovski, an Austrian jeweler, introduced cut-glass crystals as diamond imitations. The Swarovski crystals were made of high-lead-content glass and had a permanent foil backing. Eventually they were used to imitate coloured gems as well, including rubies, sapphires, and emeralds. In 1892, Swarovski patented a mechanical glass cutter so his crystals could be mass-produced to meet the high demand.
In 1895, Swarovski moved his family business, originally located in Bohemia, to Austria near the Rhine River. Rock crystals from the area around the Rhine were known as rhinestones but the term became associated gradually with glass or paste stones.