Figure 3.
The image features three close-up views of geological samples. The top section displays a rock fragment with a highlighted area indicated by a red arrow, revealing mineral textures and structures. The middle section shows another sample with distinct internal features and a scale bar indicating zero point five millimetres. The lower right section provides a schematic outline illustrating a reaction rim surrounding a mineral structure, with clear dotted lines marking its boundary. Each section contains varying levels of detail and distinct characteristics relevant to geological analysis.Examples of reaction rims formed by ASR. The upper panel shows a photograph of a concrete cross-section (Torii and Yamada, 2017). A black rim (red arrow) is visible in the upper-left aggregate particle. White ASG is present in most parts of the image. A thin section and corresponding sketch of the reaction rim are also shown