Microscopy of sand

Sand can look beautiful under the microscope. Of course there are many different types of sand and so far I have only studied a few types with the microscope. When someone I know goes on a distant vacation, I usually ask to bring back some sand. The colours of sand grains indicate which minerals they contain. Red sand grains, for example, derive their color from the presence of iron-containing minerals. The purer the sand, the whiter. White sand consists largely of quartz (silicon dioxide, SiO2) and the less contaminants it contains, the whiter it will be. The mineral olivine is a silicate containing magnesium and iron, (Mg, Fe) 2SiO4, and its presence causes a green color in sand grains. On islands with a volcanic past you can find black sand on the beach and this sand consists largely of basalt, which was formed by the rapid solidification of lava. I have only just started doing microphotography of sand and some images are shown in this article.

Red sand from the Outback in Australia.

Sand from a beach at IJmuiden.

Sand from the Kennemerduinen, location ‘t Wed.

Sand from 'Berg en Dal', Suriname.

Sand from location ‘Vossenberg’, Meijel (Limburg).

Technique

Australia: darkfield illumination, Olympus 10/0.25. IJmuiden: brightfield illumination, Carl Zeiss 3.2/0.07. Kennemerduinen: combination of brightfield illumination and incident light, Leitz 4/0.12. Suriname: combination of brightfield illumination and incident light, Carl Zeiss Neofluar 6.3/0.20. Meijel: combination of brightfield illumination and incident light, Leitz 4/0.12.