LaserSpot

PCIGR offers a workstation, named LaserSpot, designed for the preparation, imaging, and data processing of both in-situ and micro-analysis. The LaserSpot includes a Raman spectroscopy instrument, petrographic microscope, binocular dissecting microscope, micromill instrument, and computers equipped with specialized software for imaging and data evaluation.

Raman

This instrument, a Horiba XploRA Plus μ-Raman spectrometer, enables high-resolution spectral analysis of solid and liquid samples. The compact μ-Raman instrument is equipped with a high-power 532-nm laser. The instrument has full confocal capability, thus allowing sub-surface analysis. Flexible spectral slit width, laser filter, and confocal hole enable tuning and optimization for a range of sample materials. The sensitive CCD detector ensures excellent high peak-to-background signals and is equipped with a notch filter for high-resolution analysis at low wave numbers (<120 cm^-1). The system on average has spectral resolution of 2 cm^-1 or smaller for most run settings. The instrument is typically used for solid- and fluid-phase identification, and structural analysis of minerals and other materials.

Microscopes

Two state-of-the-art Nikon microscopes, a SMZ18 research stereomicroscope and an Eclipse CiPol polarizing microscope, enable high-resolution imaging and petrographic investigation of samples, mineral separates, mounts, thick and thin sections.

With adjustable magnification up to 13.5x, the SMZ18 allows convenient macro- and micro-imaging. Uniform brightness and high S/N provide high-contrast images that enable resolving small-scale features well across the field of view. The Eclipse CiPol polarizing microscope is equipped with 4x, 10x, 20x and 40x objectives. The objectives allow for multiple observation techniques, such as brightfield/darkfield. Illumination is provided by a 100W-halogen lamp. Both microscopes can be operated with the Nikon DS-Fi2 camera and the DS-U3 digital camera controller that enables high-definition images at a resolution of 2560×1920 pixels. A PC camera control unit enables live image display and editing.

Micromill

A New Wave Research MicroMill system enables high resolution micro-sampling of solid materials for geochemical and isotope analyses. The instrument can be equipped with different drill bits of various thicknesses and shapes, allowing for three-dimensional spatial resolution in the micrometer range. A fully software-controlled, motorized stage is used to set exact drill bit positions with microscope video parfocal adjustments. The software can be programmed to execute sample traverses or maps, and can also be used calculate the volume of excavated material.

The instrument is typically used for analyses where other in-situ micro-sampling approaches (e.g., laser ablation or electron-probe micro-analysis) do not liberate enough material to enable the required analytical precision. Thus, applications for the MicroMill include d¹³C or d¹⁸O analyses or high-precision isotope (e.g., Sr, Nd, Pb) analyses by TIMS or MC-ICP-MS.

Software

The software program for time-resolved analyses Iolite v.3 (https://iolite-software.com/) is installed on both computers. In addition, standard tables and a compilation of long-term values for NIST SRM612, NIST SRM610, and BCR-2G are available for QA/QC purposes.

The Nikon imaging software, NIS-Elements (version 4.30.1), facilitates documenting, processing, and editing images of samples. It can also be used for identifying sampling locations before and after analyses. The software is capable of image capture up to 2560×1920 (8-bit), and has manual and automatic options for both exposure and colour. Scale bars (based on known magnification) and annotations can also be added to image captures.