Siderophyllite

Spectrum Details

Modality

NIR

Category

mineral

Material Type

Phyllosilicate

Sample ID

NMNH104998

Collection Locality

Brooks Mountains Seward Peninsula, AK

Spectral Purity

1b2c3c4_ # NMNH104998 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

Composition / XRD

NONE # XRF, EPMA, ICP(Trace), WChem COMPOSITION_TRACE:

Sample Description

IMAGE_OF_SAMPLE:

XRD Analysis

40 kV - 30 mA and 6.5-9.5 keV (sidphyl.out, smear mount); 45 kV - 35mA and 7.3-9.5 keV (siphyl2.out, random or bulk mount) References: Pattern for siderophyllite 1M in MSA Rev. Min. 13, p. 581; Huebner's reference patterns for micas Found: trioctahedral 1M mica, subordinate chlorite and calcite (X-ray); immersion oil examination chlorite >= mica >>> carbonate Sought: quartz [(101) reflection obscured; a very weak peak observed in the position of the quartz (100)] Comments: At least three phases present. The mica pattern is consistent with siderophyllite. Sharp reflections suggest mica is well crystallized and compositionally homogeneous. The mica has a relatively large (002) spacing at 17.8, suggesting the presence of a large cation such as K. The chlorite (001) reflection is anomalously weak relative to the other chlorite reflections observed. Observed eight weak calcite reflections but found only a trace of carbonate in immersion oil, suggesting that the carbonate may not be homogeneously distributed. J.S. Huebner and J. Pickrell,T. Schaefer, unpublished data, written communication, USGS, Reston, VA (1994)

X Units

cm⁻¹

Y Units

Absorbance

Data Points

2,126