The word crystal has Greek roots. The ancient Greeks used this word to call quartz without impurities, because it was perfectly transparent and looked like frozen ice. The Greeks used crystals to make lenses, which they used to start fires. A large rock crystal was also used to create a samovar for the Russian tsar Peter the Great. The first Russian plant that manufactured crystal was founded in the 13th century.
The idea of creating crystal glass belongs to the British. They were the first to mix lead oxides with glass. During numerous experiments they saw that the glass became more shiny and glossy and looked more expensive with the addition of lead. Lead oxides improved the quality of glass, after which it acquired transparency and beautiful gloss. Crystal’s properties, such as transparency, strength, weight and brilliance depend on the percentage of lead oxide that it contains.
Unfortunately, some people mistakenly think that it is dangerous to drink from crystal glasses. However, specialists claim that an amount of lead used for the production of crystal is insignificant. It can hardly influence human health. Nevertheless, they do not recommend storing wine in a crystal jar for prolonged periods of time. Other experts claim that after processing crystal loses its toxic properties.
The crystal creation phenomenon is shrouded in hundreds of legends. Here is one of the Medieval English legends. In the 17th century the King Jacob I banned the use of the wood for manufacturing purposes. According to his order, people were not allowed to use anything created from processed wood. The exception concerned only the shipbuilding industry. As a result, coal was burned in furnaces.
G. Ravenskoft, one of the craftsmen that worked with glass, noticed that glass items became transparent when exposed to fire. The craftsman was interested in the unexpected result and he continued his experiments. In 1676 he created crystal. The dishes crafted from this material were distinguished by their durability and transparency. The craftsman realized that this new technology could make him rich and famous. He continued to work with glass and soon he managed to create the new material that now is known as crystal.
The following types of crystal exist:
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As mentioned before, crystal is a type of durable glass that is created with varying percentages of lead. The process of manufacturing crystal is extremely difficult. The natural raw materials are melted in furnaces at a huge temperature over 2732°F (1500°C). The molten mass cools very quickly. Several people participate in the manufacturing process. Glass blowers, blowers` assistants and press workers work at furnace at the same time. Glass blowers are armed with special tubes with a rubber bulb. A drop of hot crystal is taken and the product is blown into the mold with a special rubber pear.
The blowers` assistant picks up the required amount of glass that was melted in the oven and brings it to the pressman, who controls the mold`s shape and condition.
After a product is blown out and when it has the necessary shape, it enters a furnace for annealing. Annealing is designed to cooling crystal. An item stays in an annealing furnace for 1.5 hours. The temperature in an annealing furnace is decreased from 1292°F (700°C) to 104-122°F (40-50°C). After that, the upper part of an item (that connected to the glass-blowing tube) is cut off.
Finally, a product passes the first quality control. Specialists examine if a newly created item has large bubbles inside or shape deformation. The whole item is then measured, as crystal has to be thick and the surface layer must be smooth.
Crystal items made by hand blowing are the most valuable and expensive. Each item has a unique form that can be never repeated. Crystal always needs to be finished after the manufacturing process. Items are cut and polished with acids. There are four methods for processing crystalware: carving, cutting, polishing and engraving. Recently, new methods of dish decorating appeared, where craftsmen cover crystal items with precious metals (usually, gold).
Crystal dinnerware is known for its durability. Crystal items can last more than a decade. Nevertheless, they require attention and care. Consider these recommendations to maintain your item in perfect condition.