The Microscope – Volume 66, Second Quarter 2018
IN THIS ISSUE
On the cover
A polished thin section in a tremolite schist from the Talcville mine near Talcville, NY; crossed polars. See Integrated Optical, Micro- Raman, and Compositional Analysis of Rock Samples from Former Talc Mines in the Gouverneur Mining District, New York, page 51. (Photomicrograph courtesy of Brittani D. McNamee)
Editorial | What Every Microscopist Should Know (Take the Challenge)
Gary J. LaughlinThe Microscope 66:2, p. ii, 2018https://doi.org/10.59082/HQGV4048
Excerpt: When I introduce the topic of substance examination and the study of samples to an audience of budding microscopists, I will try to persuade them that once particles are classified, they need not learn how to identify every possible example in that class until they first learn the types of particles that are encountered daily by the microscopist. The number is always far less and more manageable, and this usually puts them at ease — for a while.
The Role Integrated Optical, Micro-Raman, and Compositional Analysis of Rock Samples from Former Talc Mines in the Gouverneur Mining District, New York Collections in Trace Evidence
Brittani D. McNamee and Aaron J. Celestian
The Microscope 66:2, pp. 51–63, 2018https://doi.org/10.59082/YCHB9665
Abstract: In this study we compare the morphology and composition by polarized light microscopy (PLM), micro-Raman spectroscopy, and wavelength dispersive spectroscopy (WDS) using an electron microprobe of tailings samples from two former talc mines in the Gouverneur Mining District in New York State. The main purpose of this project was to better understand the alteration of amphiboles into talc within these samples. The interaction of these minerals along their grain boundaries is important due to the resulting asbestiform and acicular (i.e., non-asbestiform) morphologies of talc and anthophyllite within the rocks in this mining district. Intensity maps created from micro Raman imaging highlight the different mineral phases present in the samples, while the electron microprobe precisely determines the weight percent oxides of the mineral phases, which aids in their identification. Backscattered electron (BSE) imaging with the microprobe was also used to compare differing mineral compositions with the Raman maps.
Abstract: In this study we compare the morphology and composition by polarized light microscopy (PLM), micro-Raman spectroscopy, and wavelength dispersive spectroscopy (WDS) using an electron microprobe of tailings samples from two former talc mines in the Gouverneur Mining District in New York State. The main purpose of this project was to better understand the alteration of amphiboles into talc within these samples. The interaction of these minerals along their grain boundaries is important due to the resulting asbestiform and acicular (i.e., non-asbestiform) morphologies of talc and anthophyllite within the rocks in this mining district. Intensity maps created from micro Raman imaging highlight the different mineral phases present in the samples, while the electron microprobe precisely determines the weight percent oxides of the mineral phases, which aids in their identification. Backscattered electron (BSE) imaging with the microprobe was also used to compare differing mineral compositions with the Raman maps.
Observations on Temperature Variations in Liquid Mounts During Light Microscopical Investigations
Jan BurmeisterThe Microscope 66:2, pp. 65–70, 2018
https://doi.org/10.59082/CXYU2484
Abstract: The precise measurement of refractive indices (RIs) of transparent small particles in a liquid mount slide preparation (using classical light microscopy and polarized light microscopy techniques) requires exact knowledge of the slide preparation temperature, and that the necessary temperature coefficient calculation be performed for the liquid before reporting final measurement results. Commercially available RI standards for microscopy are supplied as liquids in bottles with the temperature coefficient printed on the label or available from the manufacturer. Previous proposals for temperature measurements in a microscope’s light path (as published in handbooks and online articles) may be misleading due to the large and thermally inert mass of the mercury-containing thermometer bulbs that are routinely used today. An experimental setup was devised and duly calibrated using a miniature negative temperature coefficient (NTC) thermistor as the temperature sensor and a high-resolution ohmmeter to observe temperature effects in a way that is much closer to reality than the older, obsolete procedures. The results for this particular setup show that only negligible thermal effects are observed in slide preparations containing three drops of immersion liquid. Extrapolation calculations for situations with less liquid show that, in such cases, the expected temperature effects are also small to negligible.
Critical Focus | AI: Artificial, Yes. Intelligent, Not.
Brian J. FordThe Microscope 66:2, pp. 71–83, 2018
https://doi.org/10.59082/CWDQ4121
Excerpt: Why did the microbe cross the microscope? To get to the other slide. We all like jokes in microscopy (you need a sense of humor to work in the field, particularly if you have commercial clients). And what about practical jokes? Here are a couple you might like to try, and they must be high-quality pranks, for they were composed by the most brilliant of minds. First, try putting googly eyes on someone’s computer mouse so that it won’t work. Then you could hide all of the entrance to your office building if it only has one entrance, put food coloring in the mailbox, or glue all the eggs in the hubcaps of someone’s computer. Yes, this is all unmitigated drivel. These jokes make no sense at all, yet they should, for they were all devised by the wonderful brain power that people say is going to surpass us all – artificial intelligence, AI for short.
Microcrystal Tests for the Identification of Illicit Drugs: Morphine
Kelly M. Brinsko, Dean Golemis, Meggan B. King, Gary J. Laughlin, and Sebastian B. Sparenga
The Microscope 66:2, pp. 85–93, 2018
https://doi.org/10.59082/ZZNQ6918
Abstract: The Microscope is publishing monographs from McCrone Research Institute’s A Modern Compendium of Microcrystal Tests for Illicit Drugs and Diverted Pharmaceuticals (4th revision: September 13, 2021) which contains 19 different drugs and their microcrystal test reagents. This issue includes monographs for the following drug/reagents:
• morphine/gold bromide• morphine/Wagner’s reagent (IK-I, No. 1)• morphine/mercuric chloride
The previous set of monographs were published in issue 65:4 (2017): d-methamphetamine with gold chloride and platinum chloride, and dl-methamphetamine with gold chloride and platinum chloride. Monographs for remaining microcrystal tests will be published in subsequent issues.
Afterimage | Trioxane Fusion Prep
Andrew A. Havics — pH2, LLCThe Microscope 66:2, p. 96, 2018
A thin-film fusion preparation of trioxane spontaneously cooled after melting between a slide and coverslip over an alcohol lamp. The interference colors are anomalous due to variation with wavelength of the refractive indices and thinness of the prep; crossed polars with a Red I compensator.
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