Letter from Major Delafield to the Columbian Institute, January 21, 1821

Washington Jany 21. 1821 [[underlined]] For the Columbian Institute.[[/underlined]] I have the pleasure to present, /thro. Doctor Huntt/ to the Columbian Institute, two specimens of the Sulfate of Strontian; the one, the fragment of a large tabular chrystal; the other the fibrous variety. As this substance has but few known localities in the United States, and as the locality from whence these specimens came, is thought both remarkable and interesting, the following description may be acceptable. The Sulphate of Strontian abounds in the lime stone of some of the Islands of Detroit ^[[insertion]] River [[/insertion]]. in the Islands known as the Bass Islands in Lake Erie; and on the main[[strikethrough]]e[[/strikethrough]] shore of Lake Erie in the neighborhood of Sandusky. The most remarkable locality however is upon one of the Bass Islands, now called Strontian Island, four miles West, of the well known Put-in-Bay-Island. The present specimens are from this locality. The shores of Strontian Island are of perpendicular limestone cliffs, and every where is seen the opaque, white and massive Sulphate of Strontian, filling cavities in the lime stone. On one side of the Island, the Rocks have been lately rent by severe frosts, or other causes, and projected into the Lake, and here is exposed a vein of this mineral, of great beauty and

extent. This vein as now exposed is about three feet in depth, forty feet in length, and its extent into the Island unknown. It is parallel to the adjacent rocks, and horizontal to the waters of the Lake. It consists of the regularly chrystalized, the fibrous, and the foliated Sulphate of Strontian, unmixed with any foreign matter whatever, other than a little clay, in the cavities, or between the interstices of chrystals. The chrystals partake of all the forms described in the works of Profr Cleveland, under this head, and of some others arising from singular combinations, preserving however like angles. They are sometimes in masses forming steps, and cuneiform. They are opaque, translucent, and beautifully transparent: are iridescent, and of double refraction; are white, bluish white, and occasionally tinged with green. The tabular chrystals of six sides, with summits of four sides, are usually the most limpid. They are of various sizes. The largest perfect tabular chrystal I possess is six inches long, three inches wide, and two and a half inches thick. Fragments of chrystals were obtained, that belonged to some, of much larger dimensions. I took away [[end left page]] [[start right page]] the summit of a chrystal simply, that is five inches wide. Fibrous Sulphate of Strontian. This variety abounds in the same vein. The fibres are parallel to each other, and commonly perpendicular to the limestone bed. It is of a pure white, always having a strong lustre; and is sometimes a compound of translucent and transparent fibres, forming beautiful specimens. It is also iridescent. This variety may be had in masses of any size, not to exceed too great a bulk to support its own specific gravity - Foliated Sulphate of Strontian. This variety is found in the same vein. I regret that a specimen does not accompany this description. It [[strikethrough]] is [[/strikethrough]] occurs in better specimens, detached from the vein, in cavities of the lime stone. Grosse Isle Detroit River, is perhaps the best locality for this variety - It is there found in handsome fascicular groupes. The chrystals are translucent and transparent, and vary from white to dark blue. I should be gratified to lay before the Institute, and account of the minerals, fossils, and organic Remains, that I have been led to observe, and collect, upon the

shores and Islands of our Northern Lakes. Their great variety and interest, would require more labor to explain than it is in my power to bestow, but should an opportunity offer, it will afford me pleasure to present the Institute with specimens of the Minerals and Remains of the Great Lakes. Jos: Delafield.