IGNEOUS  

(Class pack of 20 - $8 unless noted otherwise)

See price schedule for cost of larger sizes.

SHONKINITE through WELDED TUFF

SHONKINITE, IG-125. Cost A. California.
Medium to coarse grained dark brown mica,
pink feldspar and pale green pyroxene.

SYENITE, IG-130. Cost A. California.
Medium to coarse grained tan to reddish alkali
feldspar with up to 5% mafics.


NEPHELINE SYENITE, IG-130A. Cost A.
Canada. Medium to coarse grain nepheline with
5 - 1 0% pyroxene, biotite and minor plagioclase in
1- 5 mm grains.

HORNBLENDE SYENITE, IG-130B. Cost A.
Canada. Very coarse grain, about 50% reddish
to brown alkali feldspar.

SYENITE PORPHYRY, IG-130D. Cost A.
Nevada. Spectacular. With euhedral
orthoclase phenocrysts in aphanitic yellow-
brown alkali feldspar groundmass.

TONALITE, see under DIORITE

TRACHYANDESITE PORPHYRY, IG-135.
Cost A.
California. Known as "Table Mountain
Latite". Vitreous plagioclase laths to 1 cm in
dark gray, aphanitic ground. 

TRAP, see BASALT

TUFF, IG-140. Cost A.
California. Light
pinkish buff, fine grain. A few 2-10 mm or
larger lapilli (brown) and up to 3 mm
conspicuous grains of quartz.

LAPILLI TUFF, IG-140A. Cost A.
California.
Fine grain, gray, various colored lapilli around 1
cm and up.

WELDED TUFF, IG-140B. Cost A.
Colorado.
Light gray, compact, fine grain. Lapilli to 1 cm.

TUFF, IG-140C. Cost A.
California. Quartz
and glassy feldspar (1-2 mm grains) in light
pinkish lavender, fine grain ash.

TUFF, IG-140D. Cost A.
California. 5-15 mm
light gray lapilli and scattered glassy 1-2
quartz in fine gray ash.

TUFF, IG-140E. Cost A.
California. White,
fine ash with 1-5 mm quartz and dark brown
lapilli to 2 cm.

WELDED TUFF, IG-140F. Cost A.
California. Pinkish brown with 1-2 mm glassy
feldspar, quartz and other volcanic fragments.

WATER LAID TUFF, IG-140G. Cost A.
California. Pale greenish white, fine grain,
stratified.

WELDED TUFF, IG-140H. Cost A.
California. Resinous, red-brown, inter-
laminated with black obsidian. 2x3 largest
size.

TUFF, IG-140I. Cost A.
Nevada. Light
buff, medium grained, somewhat friable, lapilli
to about 15 mm.

TUFF, IG-140J. Cost A.
Nevada. Grayish
lavender, medium grained with a few larger
fragments.

WELDED TUFF, IG-140K. Cost A.
California. Abundant 1-2 mm glassy quartz
and feldspar grains in a gray, fine grain
matrix.

WELDED TUFF, IG-140L. Cost A.
Nevada.
Reddish brown, eutaxitic lapilli. 1-2
quartz, plagioclase, sanidine to nearly 1/3 of
rock in a devitrifted matrix.

RHYODACITE WELDED TUFF, IG-140M.
Cost A.
Nevada. Spectacular. Abundant
broken crystals of quartz, sanidine,
plagioclase, biotite and hornblende in highly
deformed, flattened glass shards and lapilli.
Shards are from black to brown and give the
rock a laminated look.

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