CARBONATITE, IG-35. California.
Red, brown and/or pink. medium to coarse
grained carbonate rock carrying some bastnaesite.  OOS

CINDERS (VOLCANIC), IG-40. Nevada.
Dark gray scoriaceous. Average 3-15 mm.
Packed in 4 mil plastic bags equivalent to listed
rock sizes.  Check.

DACITE - check for availability

DIORITE, IG-55. Cost A. California. Medium to coarse
grain. Hornblende mafics from 1/3 to 50% of rock.

QUARTZ DIORITE (TONALITE), IG-55B. California. Medium to coarse grained with
hornblende, biotite and conspicuous quartz.  Check for p&a.

DOLERITE, see DIABASE

DUNITE, see PERIDOTITE

FELSITE, IG-60. California. White to
slightly brownish. aphanitic. May show minor
dendrites.  Check.

GABBRO, IG-65. Cost A. California. Medium
grain, medium gray color.  Some broad plagioclase lathes.

GABBRO (NORITE), IG-65B. 
California. Coarse to very coarse
grained gray plagioclase and green hypersthene.  Check.

GABBRO (NORITE), IG-65C. California.
Medium grained with an overall grayish green color.  Check.

GABBRO, IG-65D. Cost A. Minnesota.
Medium to coarse grained with broad plagioclase tablets up
to 15 mm long.  Check.

OLIVINE GABBRO (TROCTOLITE), IG-65E
California. Poikilitic
feldspar in granular olivine with minor plagioclase.  Check.

GABBRO (NORITE), IG-65F. 
Stillwater Complex, Montana. Medium to coarse grain.
Light yellowish gray matrix.  Mafic grains are bronzite.

Plagioclase is calcic and augite is present to 25%.  Check.

GRANITE, IG-70. 
Medium to coarse grained, hornblende-biotite. Porphyritic pale pink

alkali feldspar.  Some plagioclase present.  

This is one of several basic granites suitable to clearly displaying 

granite characteristics to new earth science students.  Also see IG-70O

from Texas - deeper pink color, the IG-70O is our "basic" granite for

teaching purposes.

GRANITE, IG-70A. Silver
Plume Batholith, Colorado. Medium grain, pinkish gray,
biotite-rich.

GRANITE (ALASKITE), IG-70B. 
Texas. Reddish pink, medium to coarse
grained, rare mafics.

GRANITE (GRAPHIC), IG-70C. 
Colorado. Runic quartz in pink alkali
feldspar cleavage.

GRANITE PEGMATITE, IG-70D. 
Very coarse alkali feldspar (occasionally

plagioclase). Muscovite mica and quartz.  Class pack pieces will contain

at least two of the three, and usually all three.  Check.