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.

Porphyritic Hornblende DACITE IG - 41. Shasta County, California.

Numerous hornblednde lathes up to 5mm in a fine grained light buff colored DACITE.

DIORITE, IG-55. 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. California. San Marcos Formation

Medium grain, medium gray color. Some broad hornblede lathes up to 6cm.

An idealized teaching Gabbro.

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. Minnesota.
Medium to coarse grained with broad plagioclase tablets up
to 15 mm long.  Check. Out of Stock

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

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

Plagioclase is calcic and augite is present to 25%.  

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. 
Reddish pink, medium to coarse
grained.

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

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

plagioclase). Muscovite mica and quartz.   Check. Available