...Foraminifera are useful in scientific sense as they allow to determine the change of coast lines over the time.
Thanks Bob! I am reading that Foraminifera are now considered important indicators and sensors of global climate changes, since their building of the shells ("tests") depends on CO2 level in the oceans, on the marine water acidity, etc.
The clear is quartz, pink is garnet (some with inclusions), black are iron/metal oxides. Brown looks like root beer soda bottle:)
Thanks geo_man. Agreed about the root beer. Luckily my samples appear to be devoid of anthropogenic articles.
Here is a way to isolate iron oxides: I keep my pieces of neodymium magnet within a plastic test-tube, for safety reasons, since they are very strong magnets indeed. I wiped it along the heap of sand, and, lo and behold, several 3mm size grains, probably of iron oxide (magnetite), were attracted to the test-tube and attached to it, so picked out of the heap. An "ordinary" magent of the same size is not sufficiently powerful to extract the magnetite from the sand.