Discovered in 1839 by C.G. Mosander in Stockholm, Sweden. Lanthanum is a soft, ductile, white metal which oxidises rapidly in air. It is one of the most reactive of the lanthanide group of elements, reacting with water to produce hydrogen gas. It has an abundance in the earth's crust of 32 ppm. At very low temperatures, lanthanum is super conducting (at 6K). It is used to manufacture special grades of optical glass which have specific refractive properties. Lanthanum can also be used in flints, and La³⁺ is used as a biological tracer for Ca²⁺. Radioactive isotopes of lanthanum have been tested for the treatment of cancer.Powder - Small particles with an approximately defined size range. Those materials described as alloy precursors are not true alloys - they are made by sintering a blend of powders of the component metals to achieve alloying by diffusion. The resultant cake is ground and sieved to the required particle size range. Unless otherwise stated, the particle sizes shown are for guidance only. We do not guarantee either any particular size distribution between the quoted minimum and maximum sizes, or a specific particle shape.