Looking at the blueberries on Mars, I am reminded of the fact that some crabs at the seaside eat the sand and produce small balls of sand that they have removed all the "yummy bits" from. I was wondering if the larger blue diamond-shaped 'stones' are in fact some kind of crab. I suppose if there was no predator, then they would not need to go down holes to hide or if they were land-based ones, then they probably move fairly quickly.
There do seem to be an awful lot of these diamond-shaped 'stones' about and so I was also thinking that this might be the reason there are so many - that they are crabs and not stones!
Being blue and having blue shells, they may produce "blue glue" or saliva to colour the balls blue or there might be something in the soil that makes it blue?
