Cuprite

Spectrum Details

Modality

FTIR

Category

mineral

Material Type

Oxide

Sample ID

HS127.2B, HS127.3B, HS127.4B

Collection Locality

Butte, Montana

Spectral Purity

1b2_3_4_ # Cuprite HS127.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2c3c4c # Cuprite HS127.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2_3_4_ # Cuprite HS127.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

Composition / XRD

None # XRF, EPMA, ICP(Trace), WChem

Sample Description

This is a relatively pure cuprite sample (analysis indicate 0.008% by weight Fe). Transition of the cupric ion in the cuprite crystal field results in absorption feature at 0.85µm. Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1971, Visible and near-infrared spectra of minerals and rocks: III. Oxides and hydroxides. Mod. Geol., 2, pp. 195-205. Grain size fractions are indicated by the extension after the sample number: .2B = IMAGE_OF_SAMPLE:

XRD Analysis

40 kV - 30 mA, 6.5-9.5 keV File: cupr127_mdi (smear mount on quartz plate) References: JCPDS #41-254, 41-1390; Huebner's reference patterns Found: cuprite, malachite, minor quartz, unindexed reflection at 3.23 Angstroms Comment: Cuprite and quartz reflections sharp, indicating good crystallinity. Many malachite reflections could be indexed and compare well with a weak reference pattern of malachite from the SSH collection. J.S.Huebner, J.Pickrell, T. Schaefer, written communication(1994 USGS) Also:::: 40 kV - 30 mA, 6.5-9.5 keV File: cupr127.out, *.mdi; cupr127b.out, *.mdi References: JCPDS #41-254, 41-1390, 4-836, and Huebner's reference patterns Found: Cuprite >> quartz > malachite, copper (?), unidentified weak reflection at 3.23 Angstroms Sought but not found: chalcocite, covellite, digenite, chalcopyrite, pyrite, goethite, hematite, magnetite, brochantite, atacamite, antlerite, azurite Comment: Strong and sharp cuprite pattern - the material is well crystallized. All other reflections of moderate to very weak intensity. The quartz identification is based on the (100) and (101) reflections only. Malachite is based on five very weak reflections. The copper is based on a weak (111) and very weak (220). [The copper (111) could be pyrrhotite (10-12), but that would leave unexplained the reflection at the position of the copper (220).]

X Units

cm⁻¹

Y Units

Absorbance

Data Points

1,801