G. W. Hawes—The Greenstones of New Hampshire. 188 
crystalline. The pyroxene shows the characteristic cleavage, 
as indicated in the figure and also exhibits bright colors 
between the nicols, such as are seen in the pyroxene of figure 
4, The feldspar looks impure and is filled with rifts and with 
numerous particles of chlorite and amorphous matter yet shows 
its characteristic bands of color between the nicol prisms. 
Hornblende sometimes replaces the pyroxene in these rocks, 
and is often present with it. The occurrence of these two 
minerals in the same rock is interesting, and the following 
analyses throw some light upon it. The first one is of a wholly 
chloritic kind, from Littleton ; while the latter, from Pittsburg, 
is of a variety containing hornblende. The specific gravity of 
each is 2°96. 
Littleton. Pittsburg. 
SNR a ce 48°79 
PA 16°57 16°97 
Perms oxide... 3 an 36 1°69 
Ferrous oxide ...._.....-. 9°40 8°97 
Manganous oxide ._..._-.- “20 "20 
ie ee 8°01 9°98 
Magness 22.2. 22 eS 6°98 
Tinea 2 SO ee, 1°20 
Meas Se ae 2°55 3°30 
THtanit Q0id 0) tb 1:20 1°10 
Seer es Aes 3°93 2°65 
Carbonié acid: 2.2 262k 1°02 
100°34 100°63 
and smaller of water, for the lime and magnesia are capable o 
replacement in either the hornblende or pyroxene. The 
Ma rock will be made a subject of further study. It seems to 
€ to be dependent upon a low grade of metamorphism at a 
- Jour, ~~ Serres, Vou. XU, No. 68—Aveust, 1876. 
