362 
DESCRIPTIVE MINERALOGY. 
pletely invests large spinelles, and sometimes with such regularity that it might be mistaken 
for a real octahedron of clintonite. 
This mineral was discovered about fifteen years since, and named Clintonite, by Messrs. 
J. Finch and Mather and Dr. Horton. I soon afterwards examined it, and satisfied myself 
that it was a distinct species, although I did not go through a complete analysis. It was 
subsequently analyzed by Mr. Clemson as above stated, and named by him Seybertite. Still 
more recently, Dr. Thomson examined the mineral, and arriving at the same conclusion in 
regard to its being a distinct species, gave it the name of Ilolmesite, in compliment to Dr. 
A. F. Holmes of Montreal. Mohs describes it in the body of his work, under the trivial 
name of Clintonite; and in his appendix, introduces Seybertite as if distinct. The name 
Clintonite was given to it by the discoverers in honor of De Witt Clinton ; and as all the sub¬ 
sequent examinations have proved their opinion that it was a distinct species, to have been 
correct, it seems to be proper that this 
name should be retained. It has been ge¬ 
nerally adopted by the German mineralo¬ 
gists, and those of New-York certainly will 
not hesitate to follow the example. 
Figs. 375 and 376 represent the second¬ 
ary crystalline forms observed by Dr. Hor¬ 
ton. The measurements have not been 
ascertained. 
Fig. 376. 
ANDALUSITE. 
[From its having been first found in Andalusia in Spain.] 
Made. Hauy and Cleaveland. — Andalusite. Shepard. — Andalusite and Chiastolite. Phillips. — Andalusite, or 
Disilicate of Alumina. Thomson. — Andalousite. Beudant. — Prismatic Andalusite. Jameson. — Prismati- 
scher Andalusit. Molis. 
Fj g- 377 - Description. Colour red and grey. Streak white. It occurs 
regularly crystallized, and massive. Primary form a right rhombic 
prism. Fig. 377. M on M' 91° 2CK. Cleavage parallel with M on 
M', distinct. Fracture uneven. Lustre vitreous. Feebly translu¬ 
cent. Hardness 7.5. Specific gravity 3.104. Before the blowpipe, 
it is infusible alone; with borax, it fuses with great difficulty, and only 
when reduced to powder, into a transparent colourless glass. It is not 
acted on by acids. 
The species formerly known under the name of Made or Chiastolite, is now thought to be 
a mixed mineral, consisting of andalusite and the materials of clay slate, which assumes a 
variety of compound forms. 
