ClipArt ETC
"A concretionary stone or pebble, hollow inside, and often having the walls of the cavity lined with crystals." -Whitney, 1911

Quartz Geode

"A concretionary stone or pebble, hollow inside, and often having the walls of the cavity lined with…

Pebble cup mortar. Crafted during the Reindeer age.

Reindeer age articles, Pebble cup mortar

Pebble cup mortar. Crafted during the Reindeer age.

Section to show normal progressive overlap of the formations and their shoreward change from muds to sands and pebbles.

Progressive Overlap

Section to show normal progressive overlap of the formations and their shoreward change from muds to…