Calamine brass slowly phased out as zinc smelting techniques were developed in Europe, which produced metallic zinc more suitable for brass production than calamine. However, the conversion away from calamine brass manufacture was slow; a British patent was awarded to William Champion in 1738, but the alloying of metallic zinc and copper to produce brass was not patented until 1781 (by James Emerson), and calamine brass mills persisted in South Wales until as late as 1858. The slow diffusion of this technology was probably the result of economic factors. Calamine brass Calamine brass is brass produced by a particular alloying technique using
Metallic bonding of this form of condensation. At high pressures it is a metal. The core of the planet Jupiter could be said to be held together by a combination of metallic bonding and high pressure induced by gravity. At lower pressures however the bonding becomes entirely localized into a regular covalent bond. The localization is so complete that the (more familiar) H gas results. A similar argument holds for an element like boron. Though it is electron deficient compared to carbon, it does not form a metal. Instead it has a number of complicated structures in which icosahedral B clusters dominate.