50 CONTRIBUTIONS TO CHEMISTRY AND MINERALOGY. [bull. 167. 
Table I. — Igneous rocks. 
No. 
Name and locality of occurrence. 
Melilite-nepheline-basalt, Uvalde County, Tex. 
Nephelinite, Uvalde County, Tex 
Saxonite, Douglas County, Oreg 
Diorite, Cecil County, Md 
Gabbro, Adirondack region, N. T 
Plagioclase-basalt, Uvalde County, Tex 
Amphibole-gabbro, Alpine County, Cal 
Plagioclase-gneiss, Amador County, Cal 
Diorite, Mitchell County, N. C 
Porphyry, La Plata County, Colo 
Amphibole-gabbro, Tuolumne County, Cal 
Orthoclase-bearing basalt, UvaldeCounty, Tex.. 
Orthoclase-bearing basalt, Uvalde County, Tex.. 
Norite, Cecil County, Md 
Gabbro, Union County, Tenn 
Gabbro, Douglas Island, Alaska 
Nepheline-basanite, Colfax County, N. Mex 
Olivine-basalt, Kruzof Island, Alaska 
Diabase, Mount Ascutney, Vt 
Phonolite, Cripple Creek, Colo 
Syenite-lamprophyre, Prowers County, Colo 
Augite-andesite-porphyry, Electric Peak, Wyo. 
Pyroxenic gneiss, Calaveras County, Cal 
Labradorite-porphyrite, Michigamme iron dis- 
trict, Mich , 
Pyroxenite, Cecil County, Md 
Orendite, Sweetwater County, Wyo 
Andesite, El Paso County, Colo 
Nepheline-syenite, El Paso County, Colo 
Diorite, Butte and Plumas counties, Cal 
Quartz-diorite, Cecil County, Md 
Diorite, La Plata County, Colo 
Camptonite? San Miguel County, Colo 
Phonolite, Colfax County, N. Mex 
Augite-bronzite-andesite, Unga Island, Alaska. 
Andesite, El Paso County, Colo 
Spilosite, Michigamme iron district, Mich 
Hornblende-granite, Cecil County, Md 
Latite, Tintic district, Utah 
Monzonite, Tintic district, Utah 
Diorite-porphyry La Plata Mountains, Colo 
Trachyte-andesite tuff, Tuolumne County, Cal . . 
Diorite, Douglas Island, Alaska 
Rhyolite, San Miguel County, Colo 
Syenite, Mount Ascutney, Vt 
Quartz-mica-diorite, Tuolumne County, Cal 
Quartz-monzomte, Calaveras County, Cal 
Rhyolite, Tintic district, Utah 
Quartz-diorite, Amador County, Cal 
Trachyte, Highland County, Va 
Biotite-granite, Amador County, Cal 
Rhyolite, Crater Lake, Oreg 
Monzonite (altered), Tintic district, Utah 
Rhyolite (quartz-porphyry), Tintic district, Utah 
Rock between rhyolite anddacite, Sutter Countv, 
Cal '.. 
Syenite-porphyry, Mount Ascutney, Yt 
Granite-porphyry, Mount Ascutney, Vt 
Granite, Union County, Tenn 
Si0 2 . 
v 2 o s = 
Per cent. 
Per cent. 
38 
0.054 
40 
.042 
41.5 
none 
44 
.062 
45 
.02 
45 
.048 
46 
.046 
46.5 
.033 
47 
.05 
47 
a. 06 
47 
.024 
48? 
.048 
48 
.02 
48 
.023 
48 
.038 
48 
.055 
48.5 
.044 
49.5 
.054 
49.5 
.034 
50 
.033 
50.5 
.04 
50.5 
.045 
51.5 
.10 
52.5 
.048 
53 
.04 
54 
.022 
54? 
.018 
54.5 
.022 
54.5 
.037 
55 
.043 
55.5 
.038 
55.5 
(6) 
56 
trace 
56.5 
.046 
57 ? 
.025 
58 
.03 
58.5 
.022 
60 
.007 
60 
.024 
60.5 
.02 
62.5 
.017 
63 
a. 012 
64.5 
.004 
65.5 
trace? 
65.5 
.013 
67 
.014 
69 
69.5 
.009 
.005 
69.5 
trace ? 
70.5 
trace 
71 
.004 
71 
.021 
71.5 
.016 
71.5 
trace 
73 
none 
73.5 
none 
76.5 
none 
V 2 3 
Per cunt. 
0.045 
.035 
none 
.052 
.017 
.04 
.038 
.027 
.042 
a. 05 
.02 
.04 
.017 
.019 
.032 
.046 
.037 
.045 
.028 
.027 
.033 
.038 
.083 
.04 
.034 
.018 
.015 
.018 
.031 
.036 
.032 
(6) 
trace 
.038 
.021 
.025 
.018 
.006 
.02 
.017 
.014 
a. 01 
.003 
trace ? 
.011 
.012 
.008 
.004 
trace ? 
trace 
.003 
.017 
.013 
trace 
none 
none 
none 
Mo. 
a Approximate. 
6 Lost, but considerable. 
