Figure 1-6. Columnar calcite in a stalactite. This calcite has some crystal boundaries (at blue arrows) as straight as those of palisade calcite, but also has crystal boundaries that curve more (red arrows). The crystals diverge slightly because they radiate from the central soda straw of the stalactite. A corresponding image provides a view in plane-polarized light. An additional image showing calcite layers also illustrates columnar fabric.
     Photomicrograph was taken with polarizer at 70 degrees to analyzer; field of view is 2.3 mm wide. Haylaa Cave, Somalia; Stalagmite HL4; thin section HL4A. Sample collected by Dr. George A. Brook.
  Speleothem Image
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