Bone China is a type of porcelain that represents the whitest of all dinnerware. It has the same ingredients as porcelain with the addition of bone ash (up to 50 percent). Bone gives finished china greater strength, a bright white appearance, and a translucent quality when held up to light. Though it often appears more delicate than porcelain, it is very durable. Bone China is, however, not designed as a cookware product.
Developed by English potter Josiah Spode, bone china is known for its high levels of whiteness and translucency, and very high mechanical strength and chip resistance. Its high strength allows it to be produced in thinner cross-sections than other types of porcelain.
The first development of what would become known as bone china was made by Thomas Frye at his Bow porcelain factory near Bow in East London in 1748. His factory was located very close to the cattle markets and slaughterhouses of Essex, and hence easy access to animal bones. Later, Josiah Spode in Stoke further developed the concept, and finalized his formulation sometime between 1789 and 1793. Bone china quickly proved to be highly popular leading to it being introduced by other English pottery manufacturers. Spode’s formulation of 6 parts bone ash, 4 parts china stone and 3.5 parts china clay remains the base for all bone china which translates to 25% kaolin, 25% Cornish stone and 50% bone ash. The raw materials for bone china are comparatively expensive, and the production is labor-intensive, which is why bone china maintains a luxury status and high pricing.
All PROUNA items are made with finest bone china.
Sterling silver is 92.5% pure silver, which is why it is so much more expensive than plated items. Sterling silver can be melted and the pure silver recovered rather inexpensively. Sterling silver is traded in troy ounces, a troy ounce being equal to 31.2 grams.
The market value of silver is based on .999 or 99% fine silver, NOT sterling.
All Greggio Silver items are Silver plated or Sterling Silver
Silver Plate means coated with a thin layer of silver on the surface (measured in microns) to a base metal, most commonly copper, brass, nickel and white metal. Silver plating is a technique that has been used since the 18th century, especially in England, to provide a cheaper version of household items that might otherwise be made of silver, including cutlery, vessels of various kinds, and candlesticks.
Manufacturers are not allowed to use the word "Sterling" on plated items, so you will never see the term "Sterling Plated". Care should be used for parts exposed to high humidity environments. When the silver layer is porous or contains cracks, the underlying copper undergoes rapid galvanic corrosion, flaking off the plating and exposing the copper itself; a process known as red plague.
All Greggio Silver items are Silver plated or Sterling Silver.
All Dogale items are silver plated on the outer body.
Glass Crystal is a type of glassware in which barium oxide, zinc oxide, or potassium oxide are employed instead of lead oxide, and therefore does not have the health risks of Lead Crystal.
All Lehmann Glass items are made with lead-free crystal.