374 J. D. Dana on Serpentine Pseudomorphs 
account of it. The great piles of refuse rock that are heaped 
up near the railroad leading from the mine are, in the main, 
piles of chondroditic masses thus coated or varnished with ser- 
entine. ver the most of them the serpentine is white, a 
ind that looks much like meerschaum. 
The serpentine also penetrates the masses, and from many of | 
them a fragment of chondrodite as large as a filbert cannot be 
obtained that has not films of serpentine in or about it. Italso 
fills the cavities in the old veins that were partly filled with 
erystallizations of chondrodite, chlorite, magnetite and dol- 
omite, so that the crystals of these minerals are buried under it; 
or it penetrates the veins where there were no distinct cavities. 
Besides serpentine, there is sometimes also a coating of brucite 
(hydrate of magnesia), and occasionally this mineral is in large 
erystallizations. luorite is another of the secondary incrust- 
ing minerals, although not common; it is sometimes in pink 
ive forms, and occasionally in small amethystine cubes. 
In addition, the ore bed abounds in pseudomorphous minerals. 
Crystallizations of chlorite, enstatite, chondrodite, dolomite, 
apatite and other kinds occur converted into serpentine of vari- 
ous colors. The universal serpentinization of masses and erys- 
tals conveys the impression that the rock along all the multitu- 
dinous fissures, and, to a large extent, through the interior 0 
solid portions, had been subjected to long digestion in heate 
magnesian waters. 
ere are also other kinds of pseudomorphs, indicating great 
corroding and recomposing power in the waters, as described 
beyond. 
urther, there are species of still later origin. Implanted in 
the serpentine sometimes occur polished cubes and cubo-pyrito- 
hedrons of pyrite; and in seams in the serpentine, the mineral 
pyrrhotite, another sulphide of iron. There are also, on some 
of the surfaces of blocks, occasional small groups of crystals of 
aragonite, or thin crusts of hydromagnesite. 
II Tur PsEUDOMORPHS AND THEIR TEACHINGS. 
The pseudomorphs which have been thus far observed are of 
five groups: first (A), those consisting of serpentine, or of serpen- 
tune and dolomite combined: second (B), those consisting of bru- 
him Si : 
31°99, CaO 0-99, K.O 0°16, Na,O 0-32, ignition 0-13=101'24. He analyzed 9 
massive, faintly fibrous kind. It occurs also long fibrous, and radiated fibrous, 
separa’ 7 BF 
A brown chondrodite gave him SiO, 35:42, FeO 6°72, MgO 54:22, F1900= 
F305 aced rine, 3° 
of oxygen y flu : 
Mr. ©. A. Burt (loc. cit., p. 213) CO, 47-01, FeO 0-70, MnO 
99°03, making the ratio of carbonate of lime t 
magnesia nearly 1: 1. 
