ADAMELLITE QUARTZ MONZONITE), IG-5.
Cost A. California. Medium to coarse grain, light
pink, minor biotite in 1-3 mm grains.

ADAMELLITE (QUARTZ MONZONITE)IG-5A
Cost A. California. Medium to coarse grain
light gray, 5-10% biotite.

ADAMELLITE (QUARTZ MONZONITE) PORPHYRY,
IG-5B. Cost A. California. 5-10% pinkish
alkali feldspar phenocrysts to 1 cm in a medium
grain groundmass 20% biotite.

ADAMELLITE (QUARTZ MONZONITE), IG-5C .
Cost A. Sierra Nevada Mts., California. Coarse grain, white
plagioclase and pink alkali feldspar About 10%
biotite.

ADAMELLITE (QUARTZ MONZONITE) PORPHYRY,
IG-5D. Cost A. Sierra Nevada Mts., California. Similar to
IG-5C above, but this has pink orthoclase
phenocrysts to 3 cm.

MUSCOVITE ADAMELLITE (QUARTZ MONZONITE),
IG-5E. Cost A. Nevada. Looks like flesh
color, medium grain granite. Allotriomorphic-
granular quartz, K-spar altering to a clay,
oligoclase altering to white mica, and muscovite.

ALASKITE, see under GRANITE.

ANDESITE PORPHYRY, IG-10. Cost A.
California. White plagioclase crystals to 5 mm
in compact blue-gray groundmass.

ANDESITE PORPHYRY, IG-10A. Cost A.
Inyo Mts., California. Phenocrysts of white
plagioclase and occasional quartz to 1 cm in
gray matrix.

ANDESITE PORPHYRY, IG-10B. Cost A.
Inyo Mts.. Califomia. Phenocrysts of white
plagioclase to 1cm and 2 cm biotite in reddish
brown ground.

AMYGDALOIDAL ANDESITE, IG-10C. Price
1. California. Amygdules, usually lined with
analcite crystals in brown andesite matrix.

HORNBLENDE ANDESITE, IG-10D. Cost A.
Nevada. Porphyritic. About 15% black
vitreous oxyhornblende phenocrysts to 1 cm
in dark gray matrix.

HORNBLENDE ANDESITE, IG-10E. Price
I . Nevada. Similar to IG-10D, but 10%
hornblende and scattered augite
phenocrysts in disseminated hematite-
rich reddish gray groundmass.

HORNBLENDE-AUGITE ANDESITE, IG-10F
Nevada. Porphyritic with 1-3 mm
phenocrysts of augite, hornblende and
hypersthene in descending order) as a
third of the grayish rock.

HORNBLENDE-AUGITE ANDESITE, IG-10G
. Cost A. Near Belleville. Mineral
County, Nevada. Porphyritic phenocrysts of
augite hornblende, plagioclase to 3 mm in
black aphanitic groundmass. Microscope
shows a possible mingling of two magmas to
produce this dense black andesite which
looks like basalt. .
AUGITE ANDESITE, IG-10H. Cost A.
Nevada. Porphyritic with 0.2-2 mm
phenocrysts of andesine and augite in light
reddish gray partially devitrified glass.

PORPHYRITIC ANDESITE, IG-10I. Price
1. California. Thin, black hornblende laths
to over 5 mm long in fine grain gray
groundmass .

PORPHYRITIC HYPERSTHENE ANDESITE
, IG-10J. Cost A. Nevada. Waxy, near
black glassy looking matrix with several mm
phenocrysts of labradorite, hypersthene,
quartz.

ANORTHOSITE, IG-15. Cost A. California.
Light gray to light lavender-gray andesine
feldspar with occasional minor hypersthene
or chlorite.

ANORTHOSITE, IG- 15A. Cost A. New York.
Dark gray to nearly black labradorite

BASALT, IG-20. Cost A. California. medium
fine grained, gray olivine basalt with minor
vesicles up to 1 mm.

BASALT, IG-20A. Cost A. San Gabriel Mts.,
California. Dense, fine grain, nearly black.
Scattered phenocrysts of plagioclase and olivine
up to 3 mm.

VESICULAR BASALT, IG-20B. Cost A. California. Dark
gray, fine grained olivine basalt with vesicles
from 2 to 10 mm or larger.

AMYGDALOIDAL BASALT, IG- 20C. Cost A.
Oregon. Dense, aphanitic, black with
amygdules from 5 mm to over 1 cm lined or filled
with abundant zeolite. 2x3 largest size.

BASALT, IG-20D. Cost A. California. Dense
medium-fine grain, nearly black with
conspicuous olivine grains around 2 mm.

BASALT, IG-20E. Cost A. California. Dense
medium-fine grain, gray, 2 mm grains of
conspicuous olivine.

BASALT, IG-20F. Cost A. California. Dark
gray, fine grain, 1-2 mm irregularly shaped
vesicles, plagioclase and olivine crystals up to 5
mm.

VESICULAR BASALT, IG-20G. Cost A.
California. Reddish brown, flattened and
elongated vesicles 1-10 mrn, scattered
plagioclase crystals up to 3 mm.
phenocrysts of andesine and augite in light
reddish gray partially devitrified glass.

BASALT, IG-20H. Cost A. Nevada. Dense,
black, aphanitic.

BASALT, IG-20I. Cost D. Deccan
Formation, India. Grayish green, some light
to dark mottling, aphanitic.  Check.  Class pack - $10.

TRACHYTIC BASALT, IG-20J. Cost A.
Nevada. Fine grained, gray, trachytic
matrix.

VESICULAR BASALT, IG-20K. Cost A.
Nevada. Hypocrystalline ground, abundant
1-5 mm flattened vesicles. Thin section
reveals plagioclase, augite, olivine,
magnetite and brown glass.

XENOLITHIC OLIVINE BASALT, IG-20L.
Cost C. Nevada. Nearly black, 3 or 4 to
30 mm masses of olivine torn from the
mantle, occasional phenocrysts of
plagioclase and abundant black pyroxene.  Class pack - $10.

PORPHYRITIC BASALT, IG-20M. Cost A.
Idaho. "Bird track" arrangement of
plagioclase laths averaging 1x6 mm in
medium gray matrix.   Check availability.  Class pack - $10.

PERIDOT with BASALT, IG-20-P.  Cost L.  San Carlos Indian 

Reservation, Arizona. Rich clusters of consolidated peridot sand. Crystal 

size up to 3 mm with surrounding basalt matrix.  No class pack of 20 pieces.  Only large display size available.

BRECCIA (VOLCANIC), IG-25. Cost A.
California. Red to brown and gray
fragments, 1 to 10 mm or more, tightly
cemented in a dull reddish aphanitic
matrix.     Check.  Class pack - $10.

Other VOLCANIC BRECCIA under RHYOLITE

CAMPTONITE. IG-30. Cost A. Arizona.
Gray, fine grained with 1-4 cm
black kaersutite phenocrysts and scattered
amygdules and vugs to 2 cm lined or filled
with calcite.