One important category of antique jewellery is paste jewellery. What is ‘paste’? In her book ‘Antique Paste Jewellery’, MDS Lewis defined it as ‘glass which has been cut into gem-like forms’. But antique paste jewellery is more than glass set into metal. It was frequently made by skilled jewellers and set in expensive metals such as silver and sometimes gold.
Although discovered thousands of years ago, glass was still considered a precious commodity in the Middle Ages. Coloured glass was produced, used mainly in Church windows and in ornaments and drinking vessels, and for some jewellery. But transparent or clear glass was unable to be produced due to the lack of chemical knowledge of the time although in the 15th century, cristallo, a very clear glass like quartz called ‘soda glass’, was developed on the Island of Murano, the major glass producing centre. It is not known, however, if cristallo was used to make imitation gems for jewellery but it was certainly the clearest glass available at the time.
The need for a colourless glass grew in the 16th and 17th centuries as diamonds began to be used more in jewellery as a result of improved technology in polishing and cutting. Diamonds were expensive and out of the reach of many, so a cheaper substitute was looked for. Glass production improved and the product became clearer but it had to be molded and so lacked the sparkle of real gemstones. Rock crystal, which had a higher dispersion, that is, it showed flashes of colour, 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 higher dispersion and higher refractive index than molded glass or rock crystal and could be polished to a brilliant shine.
The next breakthrough for glass being able 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. He also invented a method of colouring foils for tinting diamonds. 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. Joan Evans, in her book ‘A History of Jewellery 1100-1870’, noted at page 151 that:
‘From the first the designs of paste jewels approximated – with a surprisingly small time-lag – to those of diamonds… It must be remembered that such men as Stras were distinguished jewellers dealing in jewels of diamonds as well as paste’.
Creating imitations of diamonds and other precious gem developed into a thriving industry, particularly in France. In 1767, 314 French jewellers formed a corporation of ‘joailliers-faussetiers’ (fake jewellers).