Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/515

 The foregoing statements however, are, of much less interest than the information which can he gained about the minerals for which the locality has been so long known. These are Strontianite, Harmotome, Brewsterite, and Calcite. They are all found in a lode which runs along the edge of the granite, in many places one wall being granite and the other gneiss. The latter rock presents in the neighbourhood of the lode a remarkable porphyritic appearance, caused by the abundance of large crystals of Orthoclase which it contains *.

The mines were first worked more than 150 years ago, by the Duke of Norfolk and Co. Then the York Building Company in 1722 took a lease of them from Sir Alexander Murray, of Stanhope, the proprietor. This gentleman had done a great deal to develop the resources »f that district of Argyllshire. He obtained the services of a Mr. Bruce to survey the property ; and an elaborate map of the district was published by him in 1733. Sir Alexander announced the Strontian mines as the most wonderful discovery of the age. The miners built a town at the place which they called New York. The only other point of interest about the history of the mines is that strontia was first recognized as a distinct alkaline earth by Crawford in 1790. Klaproth and Hope independently of him, and of each other, investigated its properties in 1793.

The original mines are four in number, and are at a level of from 600 to 800 feet above the sea, They are all in Glen Strontian ; their names are Fee Donald, Bell's Grove, Middle Shop, and Whitesmith. Of these the three latter have been allowed almost entirely to fall in. The only workings which have been carried on of late years have been at Fee Donald and, to a slight extent, at Bell's Grove. The ore is Galena containing very little silver. At Fee Donald there is a tradition of an antimony lode not now worked ; and there is a record of a steel-ore very rich in silver; but no specimens of either of these are procurable.

The only minerals worth notice at Fee Donald are Calcite, especially Paper-spar, and Morvenite, the latter being rare.

At the other three mines minerals are very abundant ; but unfortunately it is impossible at present to ascertain from what levels they are derived. The different species are almost entirely confined each to its own mine, or rather to its own rubbish heap ; for it is only in these heaps that they occur.

At Bell's Grove, Harmotome and Morvenite are extremely abundant, the opaque variety of the mineral being the commoner. At Middle Shop, Harmotome is not found, but Brewsterite appears either on decomposing granite or on calcite. At Whitesmith the rubbish heaps yield small fragments of Strontianite, associated with Brewsterite, though I have never found the two minerals on the same specimen. The larger curved crystals of Brewsterite are usually on Heavy Spar.

Whitesmith is by far the deepest of the mines, but it is also the highest up the side of the mountain.

There is nothing particularly new to be noticed about these mine-


 * During a recent visit to Norway I found this type of gneiss to be very abundant in that country, where it is known as " eye-gneiss."— Oct. 1871.