Micrograph of the Month: Dissolution of Spherulites
This post follows on from the Manganese Micrograph Mystery I posted a while ago. Blog followers will remember I posted some images of layered ruminant dung which had a distinctive black 'speckled' appearance, a bit similar but not quite the same as Mn staining. Thanks to my readers the mystery was solved through the kind contributions of Hans Huisman. Huisman is a geoarchaeologist with expertise in degradation and preservation of archaeological materials. He suggests that manganese would produce more dendritic like patterns, and that instead this appears to be iron sulphide staining. Iron sulphides include minerals such as pyrite, which can oxidise to rust . This type of staining can be recognised in OIL as having a 'metallic' lustre, or smaller particles, such as we have here, can be examined using reflectance microscopy at a high magnification. So I'll be doing that asap. For now I wanted to share this image showing the possible impact this staining has had on ...