Clark and others 2007 USGS Data Series 231
Spectral Library splib06a Sample Description

(For further information on spectroscopy, see: http://speclab.cr.usgs.gov)

TITLE: Actinolite NMNHR16485 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: NMNHR16485

MINERAL_TYPE: Inosilicate

MINERAL: Actinolite (Amphibole group)

FORMULA: Ca2(Mg,Fe+2)5Si8O22(OH)2

FORMULA_HTML: Ca₂(Mg,Fe⁺²)₅Si₈O₂₂(OH)₂

COLLECTION_LOCALITY: Unknown.

ORIGINAL_DONOR: National Museum of Natural History

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Actinolites are the intermediate members of a complete solid solution series with tremolite, Ca₂Mg₅Si₈O₂₂(OH)₂, and ferroactinolite, Ca₂Fe₅Si₈O₂₂(OH)₂, as end members. Actinolite is a characteristic mineral of the greenschist facies of metamorphism.

IMAGE_OF_SAMPLE:
NO PHOTO

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Tremolite + talc + 2.878. (Norma Vergo)

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

avg. grain size = 35µm

Mostly prismatic fibrous grains partially coated with smaller grains. These grains have inclined extinction, prismatic cleavage, and slight green color indicating presence of Fe. Grains are length slow, with angle between Z and C axes (OAP ll (010)') = 16-20 degrees. This falls into the tremolite range according to D. Shelly (1985, Optical Mineralogy, 2nd Ed., Elsevier, New York, Table 9.1, p214.) G. Swayze

Spectroscopic data in the .5 to 2.5 µm indicate a low iron actinolite, confirming the above microscopic examination. Roger N. Clark

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2b3b4b # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

LIB_SPECTRA_HED:	where	Wave Range	Av_Rs_Pwr	Comment
LIB_SPECTRA:	splib04a r 73	0.2-3.0µm	200	g.s.= 35 µm
LIB_SPECTRA:	splib05a r 119	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib06a r 235			g.s.=
LIB_SPECTRA:	splib06a r 247			g.s.=