Basalt lava volcanoes can erupt with great force and fling large blobs of molten rock thousands of feet into the air. These can be launched so high that the rock has time to cool and solidify before it hits the ground. If it wasn't bad enough being hit with hot molten rock, imagine having solid boulders raining down from the sky! The consignor collected this one in Oregon near an extinct cinder-cone volcano. Its rough teardrop shape was formed as it fell through the air during a long-past eruption. This reddish brown lava bomb is about 11 x 5 x 5 inches and weighs about 3.5 pounds -- enough to really ruin your day... and this is a SMALL one! Even so, its relatively light weight is due to the incorporation of volcanic gasses in the molten rock that remain trapped when it solidified. This is called scoria and is similar to pumice, but scoria does not contain enough gas to float in water as pumice can.Date: Country (if not USA): State: OregonCity: Provenance: William Mayrsohn Collection