Volcanic Bombs

Volcanic bomb is a pyroclastic formation which was semi-molten (viscous) while ejected from a volcanic vent and is
therefore shaped while in flight. The term “Volcanic Bomb” is a term often mistakenly used by non-volcanologists to describe all sizes of formations that fall to earth already hardened. By definition volcanic bombs are larger than 64 mm in diameter. Smaller pyroclastic bombs are officially called Lapilli (plural) or Lapillus (singular).

Lapilli are a size classification term for Tephra, which is material that falls out of the air during a volcanic eruption or during some meteorite impacts. Lapilli mean "little stones" in Latin. By definition lapilli range from 2 mm to 64 mm in diameter. A pyroclastic particle greater than 64 mm in diameter is known as a volcanic bomb when molten, or a volcanic block when solid. Pyroclastic material with particles less than 2 mm in diameter is referred to as volcanic ash.

Lapilli are spheroid, teardrop, dumbbell or button-shaped droplets of molten or semi-molten lava ejected from a volcanic eruption that fall to earth hardened, or may be partially molten. These formations are the direct result of liquid rock cooling as it travels through the air. The Teardrop or almond shape occurs when a blob of lava is ejected with a spin which pulls the lava into a shape which cools and hardens before falling to the surface. We shall call these volcanic rocks “Lava Bombs” based to how they were formed. They are the smaller brothers and sisters to volcanic bombs.

Amboy Crater, San Bernadino, California

Amboy Crater is one of a chain of cinder cones extending along old US Route 66 "The Mother Road" from Amboy on the east to Pisgah Crater just west of Ludlow. Volcanic activity at Amboy occurred in the last 6000 years. The cinder cone is actually four coaxially nested cones and is surrounded by 24 square miles of basalt lave flows. "Bombs" are formed when a blob of lava is ejected with a spin which pulls the lava into an almond or tear drop form which hardens before falling to the surface. These bombs were collected from the surface of the surrounding lava flow. These small bombs are typical. The were collected over 20 years ago from the area near Amboy Crater in the Mojave Desert. This cinder cone volcano is now a National Natural Monument. Larger bombs had been picked up by generations of rockhounds and geologists. They missed these smaller ones.

Cinder cones are composed of random blocks of lava, bombs and smaller loose cinder. You will recognize cinder as maroon flower bed rock. Basalt is normally black, but since it is iron rich, it can oxidize to a reddish hue during cooling.

Specimens listed here are natural as they were found. They were only rinsed off with pure water to remove the loose dust and dirt. Photos taken in natural sunlight with the
volcanic rock dry.

Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Item# Set 1

Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California

$15.00

Sold Out!

This is a set of six (6) small "lava bombs" (Lapilli) from near the Amboy Cinder Cone in Mojave Desert in California. This set has pieces from 1.3 to 2.1" (33 to 54mm) in length and from 0.4 to 1.1" (11 to 28mm) in width and 0.4 to 0.7" (10 to 19mm) in depth. This set weighs from top left to top right; 0.12oz (3.5g), 0.28oz (8g), 0.13oz (4.5g), then from bottom left to bottom right; 0.34oz (9.5g), 0.96oz (27g), 0.58oz (17.4g).

Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Item# Set 2

Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California

$16.00

Sold Out!

This is a set of six (6) small "lava bombs" (Lapilli) from near the Amboy Cinder Cone in Mojave Desert in California. This set has pieces from 0.87 to 1.99" (22 to 50mm) in length and from 0.5 to 1.8" (13 to 46mm) in width and 0.48 to 0.8" (12 to 22mm) in depth. This set weighs from top left to top right; 1.3oz (36.5g), 1.2oz (35g), 0.38oz (11g), then from bottom left to bottom right; 0.28oz (8g), 0.16oz (4.5g), 0.36oz (10g).

Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California
Item# Set 3

Volcanic Bombs from near Amboy Cinder Cone, Mojave Desert, California

$17.50

Sold Out!

This is a set of six (6) small "lava bombs" (Lapilli) from near the Amboy Cinder Cone in Mojave Desert in California. This set has pieces from 0.8 to 3.1" (22 to 80mm) in length and from 0.39 to 1.1" (9.9 to 28mm) in width and 0.28 to 0.86" (7 to 21mm) in depth. This set weighs from top left to top right;  0.82oz (23g), 0.58oz (16g), 0.28oz (8g), 2.5oz (71g),then from bottom left to bottom right; 0.04oz (1.5g), 0.28oz (7.5g).