Contributions to Mineralogy. — Eycrntan. 45 
II. The Easton Locality. 
The minerals of the syenite ridge and contiguous rocks 
have long been known to collectors. This l^elt, appearing 
in Warren Co., N. J., crosses the Delaware river a quarter 
of a mile above Easton and extends southwesterly a distance 
of three miles, thinning out at both ends. A belt of serpen- 
tine forms the south contact between the syenyte and a gray 
blue limestone of uncertain age. Xorth of the syf^iyte is 
found the same blue limestone which forms the southern con- 
tact. The minerals occurring here (those in italics being 
rarely found) are graphite, molybdenite (in precious serpen- 
tine), chalcopyrite, chalcocite, pyrite, fluorite, galenite, gyp- 
sum, quartz, limonite, hematite, calcite, aragonite, hydromag- 
nesite, barite, cekstitc, strontiano-calcite, malachite, rircon''' 
tremolite, actinolite, asbestus, mountain leather, pyroxene, coc- 
colite, sahlite, nephrite, serpentine, bowenite, tourmaline, 
topaz, biotite, phlogopite, talc, orthoclase and prochlorite. 
Orthoclase : Being an essential constituent of the rock 
it is more or less common massive. Good crystals are occasion- 
ally found and two analyses are given, a creamy white, from 
Marble Hill, N. ]. ; b, light-red crystal, from the ridge north 
of Easton. 
Anal, 
ysls 
of Orthoc 
a 
lasc. 
h 
G. 
2.609 
2.597 
,SiO. 
65-73 
66.14 
ALO3 
17.21 
18.96 
Fe.Oa 
. 2.58 
.62 
CaO 
2.69 
.08 
K.0 
9-59 
10.79 
Na=0 
2.41 
3.00 
ign. 
.40 
100.21 
99.99 
aline: 
Generally 
■ occurs 
massive, imbedded 
in 
quartz, above the devil's oven, Bushkill creek, west of Easton. 
Good crystals up to 60 mm. showing a m planes are oc- 
casionally found, and an analysis of one of these crystals is 
appended . Some brilliant black striated crystals 40 mm , long 
have been found at Marble Hill, imbedded in ortho-jb^'e. 
• I have in my possession some dark brown crystals donbly terminated of 
fine form 15 mm. long imbedded in biotite. 
