Pyrite

Spectrum Details

Modality

FTIR

Category

mineral

Material Type

Sulfide

Sample ID

HS35.3

Collection Locality

Rico, Colorado

Spectral Purity

1b2c3c4_ # HS35.3 # 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

Forms series with Cattierite (CoS2). Dimorphous with Marcasite. "SS-19. Pyrite. Rico, Colorado (35). Pyrite, FeS2, is the most common and widespread of sulphides. It occurs in igneous, metamorphic and sedimentary rocks, as well as in veins. In the visible, pyrite displays the reflectivity vs. particle size behavior that is peculiar to opaque minerals - ie. reflectivity decreases as particle size decreases. It is also interesting that decreased absorption in the red region of the visible results in a significant contrast in reflectivity from the red to the blue, despite the sample's overall low reflectivity. In the near-infrared, the spectral behavior of pyrite changes from that of an opaque material to that of a transparent one. This sample is contaminated with grinder steel, which is probably responsible for its low reflectivity throughout. The smallest grain size is the only one which shows a rise in reflectivity to longer wavelengths, producing what appears to be an absorption edge between 1.1 and 1.5µ. We feel, however, that this is an artifact of the contamination in this sample, and that it should display a weak ferrous ion band near 1µ like marcasite, before changing from transparent to opaque behavior." Sieve interval 74 - 250µm. Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1971, Visible and near-infrared spectra of minerals and rocks: IV. Sulphides and sulphates. Modern Geology, v. 3, p. 1-14. IMAGE_OF_SAMPLE: NO PHOTO

X Units

cm⁻¹

Y Units

Absorbance

Data Points

1,801