Geochemistry and Mineralogy Core Facility

Geochemistry and Mineralogy Core  (Co-Directors: Dr. Alison Graettinger and Dr. Tina Niemi)

This research core offers instrumentation including SEM/EDS, XRD, polarized-light microscopy, and a fluid-inclusion geothermometry stage for the elemental and mineralogical characterization of solids.

The Scanning Electron Microscopy (SEM) is equipped with the energy dispersive X-Ray spectroscopy (EDS). The SEM/EDS system is used for high-resolution imaging and elemental analysis of a variety of solid sample types, including rocks and minerals, concrete and mortars, electronic and semiconductor materials, metals and alloys, synthetic catalysts, pharmaceuticals, and dried biological specimens.

The X-ray diffractometer (XRD) is used for routine identification of powdered samples of crystalline materials, singly or in mixtures, such as minerals in rocks, ceramics, concrete and mortar phases, and synthetic crystalline materials.  MDI Jade software is available for processing the XRD data.

The lab also houses a Nikon Optiphot-pol research petrographic microscope equipped for transmitted and reflected light microscopy, digital photomicrography, and determination of optical properties of crystals using a spindle stage and Excalibr software.

A Fluid Inc. gas-flow fluid-inclusion geothermometry stage is also available. This instrument can heat or cool fluid inclusions in a transparent mineral to determine the minimum temperature at which the fluid was trapped during crystal growth (by heating until the vapor bubble disappears), and to determine the salinity of the fluid (by freezing point depression).  Being mounted on a polarized light microscope, it can also be used to investigate temperature-dependent reactions, melting, and crystallization processes.

The Geochemistry and Mineralogy Core operates at the UMKC College of Arts and Sciences within the Department of Earth and Environmental Sciences (EES).

Information on the instruments:

Tescan Vega 3 LMU variable pressure SEM equipped with a Bruker Quantax EDS system and a Tescan color cathodoluminescence detector:

Instrument capabilities:

The scanning electron microscope permits moderate to high magnification images of a variety of samples to be obtained by rastering a narrow beam of accelerated electrons across a sample surface. The signal generated at each point in the raster pattern is synchronized with the raster of the image on the computer screen, providing a magnified image. Depending on the detector being used, the signal could be generated by back-scattered electrons, secondary electrons, X rays, or visible light from cathodoluminescence. The secondary electron (SE) detector is primarily used to collect morphological information from the sample. Contrast produced using the back-scattered electron (BSE) detector is related to average atomic number in the sampler, giving qualitative composition information. The color cathodoluminescence (CL) detector produces an image using the light emitted from the class=”intro-paragraph”>specimen upon bombardment with electrons. CL often reveals zoning due to variations in distribution of trace elements.

Our instrument is also equipped with a Bruker Quantax Energy Dispersive Spectroscopy (EDS) system. The EDS detector responds to the characteristic X rays generated when the sample is bombarded with high energy electrons, permitting elemental analysis of samples, including analysis at points, along lines (profiles), or elemental distribution over an area (mapping).

User Fee schedule for Tescan Vega

Rate for use of equipment (does not include labor)

Instrument UMKC   External   academic Ext. commercial
Tescan Vega 3 LMU SEM $25.00     $35.00/hr $60.00 SEM Only
with SE, BSE, and color CL detectors and Bruker Quantax X-Flash 6|10 EDS system $80.00/hr SEM+EDS/CL

Sample prep & processing

Type of prep & processing UMKC External academic Ext. commercial
Carbon Coating $5/run $5/run $5/run
12.5mm diam mounting stubs $0.23 ea $0.23 ea $0.23 ea (if kept)

The fee structure provided above is applicable to most routine sample processing. Additional fees
will be applied for difficult samples.

Printing

Images are currently available in digital form only at no charge. Users should have either a flash
drive or email address for saving the images.

Staff Support

Technical support from Dr. Murowchick $25/hr (for routine help getting started on the instrument)
Instrument Operator support $30/hr $40/hr
$90/hr

Supplies/consumables

12.5mm diam mounting stubs $0.23 ea $0.23 ea
$0.23 ea Cardboard sample box (holds 8 samples on 12.5mm stubs) $0.60 each

Rigaku Miniflex automated powder X-ray diffractometer

Instrument Capabilities:

The Rigaku MiniFlex Automated X Ray Diffractometer is a bench-top instrument well-suited for routine phase identification by XRD.  It has a relatively small goniometer radius of 150mm, providing excellent sensitivity and rapid scan speeds with a slight trade-off in angular resolution.  The instrument usually uses a Cu target, but we have a Co tube to use when fluorescence from Fe is a problem, or if larger maximum d-spacings  need to be measured.  Single samples (powdered) can be mounted on silicon zero-background plates, or a 6-sample changer can be used.  Scan parameters can be set for each sample, or one set of conditions can be used for all the samples.  Routine scan rates are 1-2 degrees/minute, but rates from 0.01 to 100 degrees/minute are possible.  The instrument has a variable divergence slit (enhancing the intensities of the high angle peaks relative to low angle peaks), but the diffractogram can easily be converted to a fixed slit equivalent in Jade.

User Fee schedule for Rigaku MiniFlex

Rate for use of equipment (does not include labor)

Instrument UMKC External academic Ext. commercial
Rigaku MiniFlex $13.00/scan $13.00/scan $25.00 scan only
Sample prep & processing UMKC External academic Ext. commercial
Sample prep & processing  $5/sample $5/sample $5/sample
Oriented mount (clays) $5/sample $5/sample $5/sample
Analysis of diffractogram $20/sample $20/sample $50/hr

The fee structure provided above is applicable to most routine sample processing.  Additional fees will be applied for difficult samples.

Output

JPEG images of the diffractograms are provided at no charge.  Users should have either a flash drive or email address for saving the images.  Diffractograms may be displayed singly, stacked, or in a 3D block diagram.  Special formatting of the output will be charged at $50/hr.

The output file can also be saved as a text (ASCII) file to be plotted by other software (Excel, MacDiff, etc.)

Staff Support

Technical support from Faculty Support  $25/hr (for routine help getting started on the instrument)
Instrument Operator support                     $50/hr                    $50/hr                                    $90/hr

Training

Users who wish to operate the diffractometer themselves must be trained in the safe operation of the instrument and its software.  Training may be obtained by enrolling in GEOL 5532 X ray Diffraction Methods (2 CH) when it is offered, or by making arrangements with Dr. Murowchick.