It has calcium carbonate as its internal skeleton in the form of microscopic needles and upon death contributes these to help form lime mud. (AmbergrisCaye.com)
The patch could also be used to deliver immunotherapeutic drugs directly to the skin tumor, through microscopic needles that are conical - shaped, a therapy that appears to be effective in mice, Ye says. (cemag.us)
The crystals are actually microscopic needle - like enzymes that are formed in the stem and leaves of the gold dieffenbachia as a deterrent to pests. (wagwalking.com)