English pewter century. Lead was removed from the composition in 1974, by BS5140, reinforced by the European directive BSEN611 in 1994. Until the end of the 18th century, the only method of manufacture was by casting and the soldering of components. From the last quarter of the 18th century, improvement in alloys (e.g. britannia metal) and techniques allowed objects to be made from pewter by stamping and spinning. English pewter While the term pewter covers a range of tin-based alloys, the term English pewter has come to represent a strictly-controlled alloy, specified by BSEN611-1 and British Standard 5140, consisting mainly of tin
Native metal brass, bronze, pewter, German silver, osmiridium, electrum, white gold, and silver-mercury and gold-mercury amalgam. Only gold, silver, copper and the platinum metals occur in nature in large amounts. Over geological time scales, very few metals can resist natural weathering processes like oxidation, which is why generally only the less reactive metals such as gold and platinum are found as native metals. The others usually occur as isolated pockets where a natural chemical process reduces a common compound or ore of the metal, leaving the pure metal behind as small flakes or inclusions. Non-metallic elements occurring in the native state include