What are these Pebbles Found these Pebbles at a lake edge where a Serpentinite belt runs through, there are lots of serpentine pebbles along this lake in Co. Sligo Ireland.



The larger pebble is 1 5/8'' a Yellowish white color underneath and translucent, and has a tiny pitted surface The smaller pebble is opaque.
The white one is milky quartz, the yellowish/brownish one could be some variation of quartz or quartzite, too.

Further information about quartz and milky quartz can be found here