It was probably 1960, I was about ten or eleven years old. Old enough to collect rocks, I even had a geological sample as a toy. It was a 12×6 inch piece of blue cardboard, with a couple of dozen rocks glued on it, and descriptions printed beneath. Over the years more and more rocks were torn off, leaving jagged patterns of white where the rocks had been. The sample of obsideon lasted for many years. I loved the smooth green stone, glass-like.

Two houses away in my neighborhood there was an empty lot. It was a corner lot so maybe it wasn’t as attractive for speculators to build on. It was part of the level flood plain near the two creeks that were a few miles north. Nothing but Spanish cattle roamed here for years, and before that it might have been on the coastal trail for migratory Costanoan Indians.

There were four or five kids that were roughly the same age, children of the post-war generation that settled into homes after building Victory ships in the local shipyards. The empty lot was a perfect neutral meeting place where parents weren’t always looking over things.

We had cleared an area of weeds in order to use the flat ground as a playing field for our purees and cat’s eyes. Marbles! The only problem was this small rock that protruded about an inch from the surface. A couple of kicks should have dislodged it, but it stood steadfast.

Someone produced a pocket knife and we dug around the edges to loosen it. We went several inches and we discovered that the small rock was looking more like an iceberg, much larger below the ground than above. There was a moment when I thought we were looking at the top of an undiscovered future mountain. I thought maybe it was best just to break off the top and level the surface with dirt. I went home to get the sledge hammer out of my garage.

With the heavy hammer over my head, I came down hard on the left side of the peak. Perhaps hundreds of kids had tripped over that peak, but now it was going to be history. Smack! A sizable piece went flying off. It worked!

Then I examined the piece and found it was smooth, and shiny green. Obsidian! It was a giant iceberg of obsidian. A few of the other kids recognized it as well. We talked about it awhile, and came to the conclusion that it wasn’t the top of a granite mountain, nor was it a house sized boulder. Obsidian was generally smaller. Perhaps we could actually dig it out. We each went back to our garages to bring back tools.

After several hours of excavating, we had a good sized boulder laying in a pit. I estimated it was about the size of a large pumpkin, about 70 lbs worth. It took all of us to roll it out of the pit. I think we just set it aside, in order to fill in the pit, level it, and get on with our game of marbles.

This morning I woke with a question. “Where did it come from?”

Sixty years later I asked the question that was unasked at the time of the obsidian iceberg. In fairness, all rocks come from the dirt so I simply accepted that at the time. Later I took a college class in geology, and I learned obsidian was volcanic. There were no volcanos nearby that corner lot. Mt. Diablo was twenty miles away, but the same college class told me that Mt. Diablo was not a dormant volcano. It was once a pimple, an island in the inland sea of California. There is even a ridge of shellfish fossils near the mountain.

The nearest active volcano is Mt. Lassen in Northern California, 240 miles away! That’s a long ways to eject a boulder. i know that the last eruption of Mt. Lassen was in 1915, and that a cabin sized boulder, called ‘Hot Rock” was ejected and ended up five miles away. It was still sizzling three days later. If the obsidian came from Lassen, it was carried to that empty lot.

It’s possible that someone found it on vacation. Then brought it home in the trunk of a 1954 Plymouth, eventually cleaning the garage out by dropping it off in the lot. People do that. But I was thinking that this was a Neolithic treasure. Something that the local tribes had traded for, chipping off sharp edged tools anytime there wished. Arrowheads, spear points, skinning knives. It may have come all the way down from the Cascades in Oregon, traded from on tribe to another, incredibly valuable until it came in close contact with a culture that had iron and steel.

In the flat tidelands of San Pablo, near Wildcat creek, there was a small settlement near the Rancho San Pablo Abode. A few buildings were there, a hotel, a few saloons, the Catholic Church. The local Natives passed by, no official reservations. If they stopped, it would have been aways off to eliminate trouble, perhaps to lighten their load by discarding things that were no longer necessary.

The obsidian came from somewhere, for a time it was treasured and valued. It ended up in a neighbor where it was dug up by children. I know for a fact that is was loaded into a toy wagon, or on top of a deadly vehicle called a “Flexy”, brought to a garage, and then hit with a sledge hammer until it was in dozens of hand sized pieces. I know this because I held the hammer. And I gave the pieces to my friends..

Always follow through with a morning question.