Bohemian glass vs Czech crystal
BOHEMIAN GLASS
The term “Bohemian” refers specifically to glass produced in the historical region of today’s central and western parts of the Czech Republic.
And what makes it so special? Well, it is renowned for its craftsmanship and the high standards upheld by glassmakers, glassblowers, glass-cutters, designers, and chandelier manufacturers. The quality is unparalleled in the world of glass artistry.
The origins of Bohemian glass trace back to the 13th century, when early glassmakers, influenced by Venetian techniques, began developing their own methods. By the 16th century, artisans had refined their craft, giving rise to what we recognize today as the glass. It reached its peak in the 17th and 18th century, when it became highly valued across Europe. Today, Bohemian glass continues to be one of the most respected and high demand glass products in the world.
Bohemian glass is primarily made from silica (sand), potash, and chalk. The production process involves several key steps:
- Glass blowing
- Cutting & engraving
CZECH CRYSTAL
Bohemian glass refers to all high-quality glassware made in the Bohemian region, which is now part of the Czech Republic.
Czech crystal, on the other hand, is a specific type of Bohemian glass that contains at least 24% lead oxide. This gives it extra sparkle, weight, and makes it easier to cut with fine detail. It’s the pieces are often cut or engraved, like luxury drinkware or chandeliers
In short:
- All Czech crystal is Bohemian glass
- Not all Bohemian glass is Czech crystal
Lead crystal is characterized by a high refractive index of light, which is manifested by substantial brilliance and the decomposition of light rays into a color spectrum. Crystal glass contains at least 24% of it. The basic material for lead crystal production is glass-making silica sand. So called batch contains not only sand, but also other raw-materials, which are weighed out in fixed rate according to the technological order, and thoroughly mixed. They include mainly potassium carbonate (potash), sodium carbonate (calcined soda ash), potassium nitrate (saltpetre) and other substances, e.g. refining agents.
Glass is melted at the temperature of 1440 °C and then formed in cast-iron or steel moulds at the temperature of about 800 °C, using blowing or pressing. Before or just after taking out the pressing from the mould, its sharp edges are melted by flame of a gas burner. The product is then cooled a bit just at place to avoid its deformation. After a very short time, it is carried to a conveyor belt lehr and it is annealed gradually to avoid spontaneous cracking of glass. When annealed, it is necessary to remove useless parts, so called caps, from blown and also from some pressed semi-products. Using cracking-off machines, a sharp flame of gas burner is used for rotational shapes; for non-rotational pieces, removing is done by manual notching, using grinding wheels or diamonds. Afterwards, sharp and uneven rims are levelled by grinding, or by flame burning in case of stemware. Matt surfaces of the products that remain after grinding or burning-off are chemically polished using special polishing devices, where a mixture of sulphuric and hydrofluoric acids is applied.