Strontium is named for the Scottish town of Strontian and was first isolated in 1808. Strontium is found chiefly as celestite and strontianite. The metal can be prepared by electrolysis of the fused chloride mixed with potassium chloride, or is made by reducing strontium oxide with aluminum in a vacuum at a temperature at which strontium distills off. Strontium is softer than calcium and decomposes water nore vigorously. The applications of strontium are similar to those of calcium and barium, but there are few advantages and the cost is much higher. Strontium 90 is a product of nuclear fallout and presents a health problem.