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: Amphibole NMNH78662 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: NMNH78662

MINERAL_TYPE: Inosilicate

MINERAL: Amphibole (specific unknown: either Na-Edenite or Mg-Hastingsite)

FORMULA: A0-1B2Y8Z8O22(OH,F,Cl)2 (A=Ca,Na,K; B=Ca,Fe+2,Li,Mg,Mn+2,Na; Y=Al,Cr,Fe+2,Fe+3,Mg,Mn+2,Ti; Z=Al,Si,Ti)

FORMULA_HTML: A _0-1B₂Y₈Z₈O₂₂(OH,F,Cl)₂

COLLECTION_LOCALITY: Canada

ORIGINAL_DONOR: National Museum of Natural History

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Sample is 0-74µm sieve interval, pale green in color.

IMAGE_OF_SAMPLE:
NO PHOTO

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Analysis by N. Vergo indicates it is an amphibole and it looks pure. She suggests either Na-Edenite or Mg-Hastingsite.

40 kV - 30 mA, 7.0-9.5 keV
File: amphnmnh.out, -.mdi
References: Borg and Smith (1969); Huebner's reference patterns
Found: Calcic clinoamphibole (tremolite-actinolite series), trace chlorite?

Comment: The chlorite suggestion base only on a peak at 7.1 Angstroms. The amphibole reflections are very sharp, suggesting good crystallinity and compositional heterogeneity.

J.S. Huebner, J. Pickrell, T. Schaefer, written communication(USGS)

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 = 20µm Range = 1 - 110µm

Prismatic grains, inclined extinction, length slow, biaxial, amphibole cleavage. All this is consistent with this sample being an amphibole. Suggest microprobe analysis to determine composition. G. Swayze.

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 322	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib05a r 925	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib06a r 1875			g.s.=
LIB_SPECTRA:	splib06a r 1887			g.s.=