Is this a fossil nest?

Asked March 14, 2018, 4:46 AM EDT

Found this rock and cracked it open and a few egg shaped objects where inside. One Broke loose. Is this a nest of some sort?

Clackamas County Oregon rock identification geology fossil identification

1 Response

What a wonderful find! It is a 'nest' of sorts. The "eggs" are secondary mineralization where silica rich waters have filled in air pockets and fractures within the volcanic rock. It appears to be agate in basalt but it's hard to say from the one image. Look at the circular lines in the quartz (agate) on the lower left of the rock image. This indicates different eras of coatings being applied to the air pocket. In basalt, the air pockets are called vesicles. Check out the Oregon Department of Geology and Minerals Industry for additional information. Good eyes!!