Malachite

Spectrum Details

Modality

FTIR

Category

mineral

Material Type

Carbonate

Sample ID

HS254.1B, HS254.2B, HS254.3B, HS254.4B

Collection Locality

Bisbee, Arizona

Spectral Purity

1b2_3_4_ # HS254.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2_3_4_ # HS254.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2b3b4_ # HS254.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2_3_4_ # HS254.4B # 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

Original spectrum published in: Hunt, G.R., J.W. Salisbury, 1971, Visible and near-infrared spectra of minerals and rocks: II. Carbonates. Modern Geology, v. 2, p. 23-30. With the following notes: "Malachite, CuCO3•Cu(OH)2, like azurite is a basic carbonate of copper. More common than azurite, it is still only a minor ore of copper, occurring as a secondary mineral in the upper oxidized zone of copper deposits. This particular sample appears to be relatively pure." "Like azurite, malachite presents an atypical carbonate ion spectrum. Apart from the broad 0.8µm band and the short wavelength fall-off below 0.52µm, due to electronic transitions in the Cu^2+ ion, only 3 bands are present. By analogy with the spectrum of pure CuCO3, we assign all three at 2.29, 2.37 and 2.52µm to the CO3" radical. Some contribution to the 2.37µm band may come from OH', but no other hydroxyl bands are visible in the spectrum, a circumstance for which we have no explanation." Grain size fractions are indicated by the extension after the sample number: .1B = IMAGE_OF_SAMPLE:

XRD Analysis

Malachite - major component Possibility of some Mcguinnessite cannot be ruled out Trace of undetermined phase Konnert, Judith and Marta Flohr, 1992, unpublished data, USGS Reston, VA.

X Units

cm⁻¹

Y Units

Absorbance

Data Points

1,801