Yellow-white metal which quickly oxidize and form a dark gray/black surface coating. m.p. 769 ºC; 1416 ºF b.p. 1384 ºC; 2523 ºF density 2.54 g/cc; 158.57 pound/cubic foot	memory peg
	1787/90 William Cruikshank & Adair Crawford, England/Ireland
	Strontian (Srón an t-Sithein), village in Scotland named by Thomas Hope in 1793

Strontium was first detected in the mineral strontianite (SrCO₃, named in 1791), found in the lead mine at Strontian (Srón an t-Sithein), on the shores of Loch Sunart, Argyllshire, Scotland. It appears that it has been known as far back as 1764, but it was not recognized as a distinct mineral until later when the examination of it led to the discovery of the new earth.

For the discovery of Strontium several chemists are credited: Cruikshank (1787), Crawford (1790), Hope (1791), Klaproth (1793), Kirwan (1794), and finally Davy (1808).

The earliest chemical work on this mineral was by William Cruikshank in 1787, and by the Irish physician Adair Crawford (1748-1795) in 1790. They concluded that it contained a new earth.

In September 1793, Martin Heinrich Klaproth published a paper describing a series of parallel experiments made with strontianite and witherite (barium carbonate). In 1794 he prepared Strontium oxide and Strontium hydroxide.

On 4 November 1793 Thomas Hope (1766-1844), professor of chemistry in the University of Edinburgh, read to the Royal Society of Edinburgh a paper, summarised in the Society's Transactions in 1794 but not published in full until 1798, in which he reported that he began to work on the mineral from Strontian in 1791 and in a series of experiments he showed that it contained a "hitherto unknown kind of earth". He called the mineral strontianite and the new earth strontia after the locality of the mine.

On 9 January 1794 the Irish chemist Richard Kirwan (1733-1812) read a paper to the Royal Irish Academy and described a number of careful experiments including the preparation of a number of salts of Strontium and of the oxide and hydroxide.

W.P. Doyle, in his biography of Thomas Hope, concluded that "the original discovery of the individual nature of strontianite must be ascribed to Crawford and Cruickshank; while Klaproth, Hope and Kirwan contributed equally and independently to the examination of the properties of strontianite and to the preparation of several compounds of strontium and their differentiation from those of barium."

In 1807-08 Sir Humphry Davy, who had previously isolated the elements Sodium, Potassium, Barium, Calcium and Magnesium, managed by similar techniques to isolate the unknown element from strontianite. In his paper read for the Royal Society of London on 30 June 1808, he referred to the new alkaline earth metals in this way (note):

The mines near Strontian. They are not open for the public. Photo by Peter van der Krogt, 18 September 2004.
If you want this photo with higher resolution, or taken from a different viewpoint, write me.

• Mary Elvira Weeks, Discovery of the Elements, comp. rev. by Heny M. Leicester (Easton, Pa.: Journal of Chemical Education, 1968), pp. 491-495.
• H. Currie. Minerals of Scotland - Website
• W.P. Doyle, Thomas Charles Hope, MD, FRSE, FRS (1766-1844).