Thundereggs from Canada
Compared to the US, Canadian thundereggs are scarce and rarely offered for sale. The specimens I have and have heard of are all from British Colombia and are described as scarce and collectable.
Black Dome [Empire Valley], British Colombia
Skeena, British Colombia
USA - Canada - Alaska - Mexico - Argentina - Peru - France - Germany - UK - Poland - Greece - Turkey - Romania - Bulgaria - Slovakia - Kazakhstan - Uzbekistan - Russia - Japan - Ethiopia - Iran - Australia - Unknown