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.

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:

av gr sz = 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 micropscpic examination. Roger N. Clark

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1_2_3_4_

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 ____ 0.2-3.0µm 200 g.s.=

LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=