TITLE: Coquimbite GDS22 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: GDS22

MINERAL_TYPE: Sulfate

MINERAL: Coquimbite

FORMULA: (Fe+3)2(SO4)3*9H2O

FORMULA_HTML: Fe2+3(SO4)3•9H2O

COLLECTION_LOCALITY: MIT Collection (Harvard Dana Collection)

ORIGINAL_DONOR: MIT Mineral Collection, Dave Sherman

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Dimorphous with Paracoquimbite.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 7.3-9.5 keV
File: coqum22.mdi, *.out (smear mount on quartz plate)
References: JCPDS #6-40, 27-254
Found: Coquimbite and subequal paracoquimbite

Comment: Very sharp reflections, many peaks slightly assymetric due to imperfect overlap of reflections. Suggest that these phases are well crystallized and compositionally homogenous. Weak unindexed reflections are present but, because we find virtually all of the reflections listed on the JCPDS cards, we suspect that the unindexed reflections are coquimbite and paracoquimbite reflections that were not recorded by the JCPDS.

J.S. Huebner, J. Pickrell, and T. Schaefer, 1994, written communication.

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

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 1249 0.2-3.0µm 200

LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=

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