These two icebergs were photographed by Oyvind Tangen on a research ship, 1,700 miles south of Cape Town and 660 miles north of Antarctica. The berg above with its distinctive stripes of dust, ground rocks and re-frozen melt water was 150 feet long and 30 feet high. The smoothness of this makes me think it's not just waterworn but has turned turtle.
This iceberg was 100 feet tall with this amazing blue stripe through the middle. The white colour of ice is due to the compressed bubbles of air which scatter light in all directions. The blue stripe is where part of the ice has melted in a crevice and re-frozen quickly enough to exclude bubbles.