What are the Raw Materials used in Crystal Making?
The raw materials for glass making are a chemical "cocktail" of silica-sand (also called silver sand), potash, and red-lead. A yellow oxide of lead called lethargy was used when lead crystal was first developed, and it is produced from red-lead oxide when some of the oxygen is driven off. Silica occurs in nature as the sand found on beaches (although sand from inland sandstone deposits is used in glassmaking) and the pure form of quartz that produces hexagonal crystals. Each glassworks factory concocts its own formula that produces the qualities needed for its particular manufacture of glass. A typical comparison of the quantities of materials that make the differences between ordinary, or table, glass and crystal follows: ordinary glass with 63% silicasand, 22% soda, and 15% limestone; and lead crystal with 48% silica-sand, 24% potash, and 28% red-lead.
Colored glass is made by adding other metals to the glass mixture. Manufacturers may also add tiny amounts of saltpeter (a nitrate of potash), borax, and arsenic to their glass recipe. Standards have been devised for the quality of crystal in which the percent of lead or other oxides, the density of the glass, the refractive index of the glass, and its surface hardness are established. Crystal glass, pressed lead crystal, lead crystal, and full lead crystal are defined differently based on these standards.
What is the proper way of Caring for Crystal ?
Because fine crystal and glassware require the gentlest of care to maintain their brilliance and integrity for years to come, we strongly recommend the following:
Wash your fine crystal and glassware by hand in moderately hot water with a mild lemon detergent and 1/4 cup ammonia (to prevent spotting). Rinse in clean water and air dry on a rack. Cleaning the crystal in an automatic dishwasher may cause the crystal to lose brilliance; we recommend you avoid this. However, if the fine crystal and glassware must be machine washed, please follow these precautions:
- Do not machine wash metal-accented crystal.
- Use your dishwasher's "fine crystal and china" setting.
- Because even the mildest brands of automatic dishwashing detergent are abrasive, use only half the recommended amount.
- Lower the top dishwasher rack, if possible, to accommodate the height of your crystal, paying special attention to your stemware.
- Make certain to space your crystal stemware on the rack so the pieces do not touch one another, since vibration during the washing and rinsing cycles can chip or crack the crystal.
For dishwashers without a "fine crystal and china" setting, turn on the "air-dry only" cycle and open the door to allow your crystal to air dry.
Remember that fine crystal and glassware can crack or break when subjected to extremes of hot and cold. Before putting very warm food or liquid into a crystal container, we recommend you preheat the crystal with moderately hot tap water. Do not pour cold beverages into a pitcher or bowl that's just been washed with hot water. Likewise, do not wash a crystal piece that's just come out of the refrigerator; allow it to warm to room temperature first.
Clean vases and decanters by filling them half-full with moderately hot water, a small amount of mild detergent, two tablespoons of white vinegar or ammonia and a cup of uncooked rice. Swirl the rice around for a few minutes to remove residue. Rinse well with moderately hot water and air dry, upside down, on a rack.
Remove more stubborn stains by filling the container with warm water and dropping in a denture-cleaning tablet; let it sit until the stain disappears.
Do not clean your fine crystal and glassware with scouring pads or abrasive cleaners.
Always store your stemware upright to help prevent chipping.
What is the history of Crystal Making?
The great glass-and crystal-making countries of Europe include the Netherlands, Czechoslovakia, England—and the City of Venice. The history of the art form in England began with the Roman occupation of Britain, and it had a number of high points including the manufacture of stained glass during the ages of cathedral building. As an industry, it reached a new level in the mid 1500s when several leading glassblowers from Venice moved to London and found the favor of Queen Elizabeth I who promoted the art form. The Venetian influx and the Queen's support made discovery of lead glass possible in the next century.
George Ravenscroft established his own glasshouse in London in 1673 and, shortly after, patented a process for making "flint glass" or lead crystal. Ravenscroft found that the addition of lead to glass during the melting process improved the quality of the glass. Early defects included the introduction of a bluish tinge and "crizzling" of the glass. Increasing the lead content in the crystal eliminated such flaws. He continued experimenting with the chemical composition of glass, and eventually eliminated the imperfections. The practice of cutting glass came into prevalence during Ravenscroft's time (previously, unadorned glass was thought to be beautiful on its own), and his invention was the perfect medium for this kindred art form. In the 1700s, the number of glasshouses in England grew tremendously, however a government tax on glass began to hurt the business.
Manufacturers escaped the Excise Tax by moving their factories to Ireland, and it was during this period that Ireland became the new center for production of lead crystal, notably in the port city of Waterford. There, George and William Penrose founded the Waterford Glass House in 1783, and, by 1851, the house won worldwide attention at the aptly named Crystal Palace Exhibition (one of the first world's fairs) in London. The profitability of the Irish glass houses also caught the attention of the tax authorities, and the tax on glass that was not instituted in Ireland until 1825 finally forced the closure of the Waterford factory during the year of its great Crystal Palace triumph, 1851.
Glass houses elsewhere in Europe thrived throughout the 1800s when Baccarat in France, Orrefors in Sweden, and Swarovski in Austria, to name only three, became leading lead crystal manufacturers. The Irish tradition did not resurface until after World War II when a resurgence of interest in the Irish arts encouraged a group of businessmen to resurrect Waterford. Today, all of the name glass houses have flocks of admirers and collectors worldwide, and they often market each others' products as a means of boosting international interest and protecting that small brotherhood of artists in glass.
What is the Future for Lead Chrystal?
Lead crystal has a promising future because it has an enduring association with both handcrafting and elegance. An "ordinary" family or collector without an extraordinary bank account will find it satisfying to build a crystal service or collection of figurines over a lifetime, and this sense of style and worth is inherited by future generations, as the pieces themselves will be. The artistry in each piece of lead crystal is also appreciated in an age of sound bites. Even the most contemporary design represents a long heritage and the skills of the artists who created it. This sense of appreciation shows every sign of flourishing in the next century, as it has in the past.