Name: Basalt
Type: rock
Class: Igneous
Subclass: Mafic
Particle Size: Solid
Sample No.: Basalt_H2
Owner: JHU
Wavelength Range: All
Origin: from Juan de Fuca Ridge, via Smithsonian (Cat. No. NMNH111276)
Collection Date: N/A
Description: The sample has a glassey rind over a more crystalline interior. It is approximately 4 x 2 cm, light gray on "weathered" surfaces and dark gray on fresh surfaces. This vesicular sample possesses small phenocrysts < 1 mm which make up about 10% of the rock. The phenocrysts consist of plagioclase laths and olivine, with plagioclase much more abundant than olivine. Original ASTER Spectral Library name was jhu.becknic.rock.igneous.mafic.solid.basal2.spectrum.txt
Composition:

Petrographic Description:  The glassy rind portions are almost apheric, with
rare plagioclase and olivine microphenocrysts (in that order of abundance).
The core of the sample consists of plagioclase and augite (?) in a 1:1 ratio
with interstitial glass.

Microprobe Analysis:  None.

Chemical Analysis:  (by William Melson, NMNH, Wash., DC)
SiO2  49.95
CaO  12.04
TiO2  1.48
Na2O  2.48
Al2O3  14.8
K2O  0.100
Fe2O3  -  1.74
H2O  0.180
FeO  9.15
P2O5  0.12
MnO  0.190
MgO  7.75
TOTAL  99.98
