Name: Basalt
Type: rock
Class: Igneous
Subclass: Mafic
Particle Size: Fine
Sample No.: Basalt_H9
Owner: JHU
Wavelength Range: All
Origin: from Kilauea, via Rosalind Helz, USGS, Reston, VA (Cat. No. KI67-3-84)
Collection Date: N/A
Description: Powder derived from sample: a dark gray, slightly vesicular rock, consisting of black and light green phenocrysts, approx. 0.5-1 mm in size, making up about 40% of the rock.Particle size was 0-75 micrometers. Original ASTER Spectral Library name was jhu.becknic.rock.igneous.mafic.fine.basal9.spectrum.txt
Compostion:

Petrographic Description:  A medium-grained porphyritic rock with olivine 
and pyroxene phenocrysts.  The groundmass consists of plagioclase, 
abundant interstitial brownish glass, olivine, pyroxene, opaques, and apatite.  
The glass analysis is given below.

Microprobe Analysis:  (by Rosalind Helz).  The average composition of the
olivine was Fo62, that of the feldspar An78 (bytownite).  Two pyroxene 
phases were probed; a high Mg low Ca pigeonite and titanaugite.  Opaque 
phases probed were ilmenite and magnetite.  Glass composition was:

SiO2  55.02
Cr2O3  0.00
TiO2  2.83
CaO  6.46
Al2O3  12.50
Na2  3.50
FeO  12.58
K2O  1.82
MnO  0.14
P2O5  0.82
MgO  2.74
TOTAL 98.41

Chemical Analysis:  (by Herb Kirschenbaum, USGS, Reston, VA.)
SiO2  49.93
CaO  10.88
TiO2  2.99
Na2O  2.51
Al2O3  13.81
K2O  0.65
Fe2O3  1.73
H2O  0.15
FeO  9.13
P2O5  0.31
MnO  0.16
Cr2O3  0.2
MgO  7.69
TOTAL  99.95
