We picked these rough agate/quartz crystals in Ayrshire in Scotland over the last few years. These pieces all share white patterns, in quartz, agate, chalcedony and that weathered agate mineral type. They are mixed clear and solid white colours that appear to be true chalcedony or quartz. There might be calcite crystal through some of them.
These minerals have a gorgeous white hue to them. There are a couple of banded pieces. They are a little small to sell individually but too pretty to discard. A lapidary artist might be able to do something with these little agates or chalcedony pebbles. You can learn more about agates on the Stone Circle blog.