These Amygdaloidal Basalt Lake Michigan Tumbles were naturally collected from the shores of Lake Michigan and polished to highlight their distinctive textures and patterns. Amygdaloidal basalt forms when gas bubbles in cooling lava later fill with secondary minerals, creating small, rounded pockets throughout the stone. Each piece reflects a unique combination of volcanic history and shoreline shaping. You will receive one intuitively selected tumble.
• One Lake Michigan amygdaloidal basalt tumble — selection will vary • Shoreline-collected and polished by us • Naturally occurring mineral-filled pockets • Ideal for collections or display
A unique geological piece shaped by both volcanic activity and Lake Michigan’s shoreline.
