210 E. S. Breidenbaugh—Minerals found at 
tion and transparency of the chlorite to the compactness and 
opacity of the serpentine. Results of analyses are— 
II. Ii. 
I. Mean. Oxygen. 
SiO, 42°27 42°30 siscthaess 42°28 22°53 
Al,O, 85 Bo wie 36 40 
FeO 2°58 2°56 dpc 2°57 69 
MgO 40°29 40°30 ive 40°29 16°11 
CaO 1°41 1°29 Se 1°35 36 
K,O seis mee tr. tr. eae 
Na,O aan pipe "48 48 cme 
O 12°58 12°47 gals 12°52 11°18 
oxygen ratio for R, §i,H is 17°26: 22°53: 11°13, or 3:1: 
4:03:23 that of serpentine being 3:4: 2. 
in thin layers parallel to the walls of the fissure. Across the 
layers at a considerable inclination to them run traces of 
The layers assume a wavy appearance, depending probably on 
the character of the fissure. thin ed i 
described above. Analyses of this variety were made in this 
laboratory, by Mr. C. A. Burt, with the following results : 
0: 
i. ean. xygen. 
SiO, 41°29 41°57 41 43 22°08 
Fe 2°13 2°07 2°10 46 
MgO 40°56 39°79 40°18 16°07 
CaO 1-08 8 ‘95 
H,O 13°61 14:00 13°81 12°28 
98°47 
This likewise gives the ratio of serpentine. ‘ 
A third variety was analyzed, of which only a few specimens 
were found. It occurs as a group of nodules, formed of 
radiated fibers, and is of a light grayish color with a greenish 
t5. H=8. 
tinge and a pearly luster. Fuses at 5. Sp. grn=24 
nalysis gave— 
Oxygen. 
SiO, 39°38 21°00 
Al,0, 1°56 ‘73 
FeO 13°87 3°08 
MnO tr. 
MgO 32°25 12°9 
K,0 ‘17 aweu 
Na,O t sues vets 
H,O 11:90 10°59 
Oxygen ratio for R, Si, His hence 8: 3°9: 2. 
