picture of the day
https://ift.tt/2QG3KHZ https://ift.tt/3bokqM7 Thin section scan crossed polarizers Siilinjärvi R636-105.90 edit.jpg Scanned image of thin section from Siilinjärvi apatite ore in cross polarised transmitted light. Actual sector size about 37 × 20 mm. March 25, 2020
