Coming from one of many thunderegg locations
around
Germany, this location produces brownish thundereggs with coarse
quartz
grains and greenish "rings" and white to light pink colors.
That's all I know about them.
Click on the pictures to see larger
and closer-up pictures.
Rough Appearance: Has
greenish pertile/tuff
attached to them with some coarse quartz crystals
sticking out.
White agate with greenish "rings" is
a dead giveaway.