The most difficult glass riddles

Cranberry glass or 'Gold Ruby' glass is a red glass made by adding gold salts or colloidal gold to molten glass. The glass is typically hand blown or molded. Legend holds that cranberry glass was first discovered when a noble tossed a gold coin into a mixture of molten glass

The green tint found in most tempered glass is a result of iron used in the production of glass sheets, where it is added as an ingredient to act as a lubricant. In fact, except in manufacturing processes designed to minimize iron use to avoid the green tint, you’ll find that green cast in all sheets of glass–not just tempered glass

Sea glass beaches are created from years of dumping garbage into an area of coastline. Sea glass begins as normal shards of broken glass that are then persistently tumbled and ground until the sharp edges are rounded.

An amorphous solid is any noncrystalline solid in which the atoms and molecules are not organized in a definite lattice pattern. Such solids include glass, plastic, and gel. An amorphous solid does not have a definite geometric or crystalline shape. Glass is an amorphous solid that exhibits a glass transition.

Legend has it the shape of the glass was modelled on the breast of Marie Antoinette. The broad surface area allows the champagne to lose its carbonation more quickly, making it not suitable for the current style of very dry champagnes. It therefore fell out of fashion except for traditional occasions such as weddings, where it is often stacked in layers to build a champagne tower.

Glass-ceramic materials share many properties with both non-crystalline glass and crystalline ceramics. The negative thermal expansion of the crystalline ceramic phase can be balanced with the positive expansion of the glassy phase. At a certain point (~70% crystalline) the glass-ceramic has a net expansion near zero and can sustain repeated and quick temperature changes up to 1000 °C.

A characteristic feature of hyalite glass is its black or red color and lack of transparency. His inventor was Georges Bouquoy, also known as Jiří Buquoy. Products made of hyalite glass were usually decorated by grinding and gold plating.

Powdered cobalt glass, called smalt, has been historically important as a pigment in painting and pottery. It is colored to a deep powder blue hue using cobalt ions derived from cobalt oxide. Cobalt aluminate can be used in a similar way, and is now more common, often known as "cobalt blue".

The narrow bowl of the champagne flute is designed to retain champagne's signature carbonation, by reducing the surface area at the opening of the bowl.