Lambrix is fossiliferous chert that varies in color, sandy yellow brown (10YR 6/4, 5/5) to pale brown (10YR 6/3) to yellow (10YR 7/5); brownish coloration grades into gray (6/1, 5/1) and light gray (10YR 7/1, 7/2) light gray mottled with veins of semi-translucent blue-gray chalcedony. It is smooth to grainy, glossy, and brittle in texture. When weathered is tan with iron oxide; has a sandy red cortex within thick layers or reddish sandstone.
Geology remarks: Epoch- Mississippian, Series- Lower Mississippian, Group- Traverse, Form- Port Huron glacial moraine resting on the Marshall formation.
Location remarks: Green Quarry, Sec. 26-35 T15 N, R 18W, Oceana County, Michigan; in a modern quarry adjacent to the Lambrix property. In glacial till beds in Oceana Co., MI, a component of the Port Huron glacial moraine.