THE METEORIC BASALTS. — GABIiRO. 



109 



Bishojmlle, South Carolina. 



The meteorite which fell at Bishopville, South Carolioa, March, 1843, has been regarded 

 as an iuteresting and peculiar one. Professor C. U. Shepard, iu 184G,* described from it, 

 under the name of Chladnitc, a mineral which he regarded as a ter-silicate of magnesia, 

 and as forming over two-thirds of the stone. The color is snow-white, rarely tinged with 

 gray. Lustre pearly to vitreous, translucent, H. G-6.5. Sp. Gr. 3.110. Fu.se.s witliout 

 difticulty before the blowpijie to a wliite enamel. He further descrihes as apatoid, small, 

 yellow, semi-transparent grains liaving a liardness of 5.5, and very rare. A third mineral, 

 which lie names iodolite, is of a pale, smalt-blue color, vitreous lustre, and brittle. Hard- 

 ness 5.5-6. Fuses ea.sily with boiling into a blebby, colorless glass. The iodolite was 

 found only in a small quantity. 



Later, Shepard gave a fuller account of this stone, holding that it contained, chladnite 

 90 per cent, anorthite 6 per cent, nickeliferous iron 2 per cent, and 2 per cent of mag- 

 netic pyrites, schreibersite, sulphur, iodolite, and apatoid. \ 



The stone was next investigated by W. Sartorius von Walter.shausen. He de.scribed 

 the principal mass as a white siliceous mineral, forming a finely crystalline mass, with 

 here and there little points showing metallic lustre, also grains of magnetite and brown 

 oxide of iron. The hardness of the white mineral is given as 6, and the specific gravity 

 as 3.039. His results indicated that the siliceous portion of the meteorite was composed 

 of 95.011 per cent of chladnite, and 4.985 per cent of labradorite. The former he found 

 to be monoclinic, and related to wollastonite in specific gravity, color, texture, hardness, 

 and crystalline form. % Later, Professor J. Lawrence Smith stated that, from some of his 

 investigations, " chladnite is likely to prove a pyroxene ; " § and subsequently published a 

 further discussion, in which he said of chladnite : " It is identical in composition with 

 Enstatite of Kenngott." || Earlier than Smith's last paper, some investigations were 

 made upon this meteorite by Professors Carl Eammelsberg and Gustav Eose. The 

 former held that the yellowish-brown and bluish-gray particles (the apatoid and iodolite 

 of Shepard) arose from the oxidation of the nickeliferous iron or the alteration of the 

 pyrrhotite. 



Rose's examination showed that the chladnite fused before the blowpipe only on the 

 the edges to a white enamel. \ Eammelsberg, in the continuation of his work, further 

 declared that no feldspar was to be found in the stone.** Through tlie courtesy of ]\Ir. 

 John Cummings and Professor A. Hyatt, the Curator of the Boston Society of Natural 

 History, I have been permitted to make a microscopic examination of a small portion of 

 this meteorite now deposited in the collection of that society. 



The portion examined is a grayish-white mas.s, resembling, as Shepard remarked, 

 a grayish-white granite (alhitic), with brown and black spots. 



Under the microscope it is seen to be composed of an entirely crystalline mass of 

 enstatite, augite, feldspar, olivine, pyrrhotite, and iron. 



The structure is essentially granitic, and it appears to belong to the gabbro {noritc) 

 variety of basalt. 



The enstatite is clear and transparent. It shows a longitudinal cleavage parallel to the 

 line of extinction, and in some specimens this is crossed by a cleavage at right angles. It 



* Am. Jour. Sci., 1846 (2), ii. 380, 381. 

 % Aim. Cliem. Pharm., 1851, Ixxix. 3G9-374. 

 II Ibid. 1864, xxxviii. 225, 226. 

 ** Ibid. 1870, pp. 121-1 2H. 



t Ibid. 1848 (2), vi. 411-414. 



§ Am. Jour. Sci., 1855 (2), xix. 163. 



% Abh. Berlin. Akad. 1863, pp. 117-122. 



