Petrified as it was, scared would not be the best way to describe it.

Shiny, smooth and colorful would do for the piece of petrified wood that was dredged up by an Island scalloper recently. And fascinating, too, would be another appropriate adjective to add after this sizable chunk of weathered wood was uncovered and its history unraveled.

Petrified wood is a fossil, a remnant of plant material that existed many, many years ago. Think millions. Try to imagine how many cells there are in a living organism, and then how long it would take to replace those cells’ organic material with inorganic material, using nothing but time and happenstance.

Some petrified wood is believed to be 300 million years old, though individual specimens can be difficult to age, since each was produced by a totally unique set of conditions. Fossilization may be truly said to be a phenomenon that occurs globally, but acts locally.

How this particular three-inch piece of history came to end up in one man’s boat will likely never be known, though we can tell a plausible story of its possible journey.

Once upon a time, a tree that stood in a faraway place fell down to the ground and was buried by volcanic ash or sediments. This was a crucial part of the process, because beneath its covering layer, the wood suffocated: With little or no oxygen present, no decomposition was possible.

Groundwater laden with dissolved minerals then flowed around this wood. (If you’ve ever seen pipes encrusted with the minerals that were deposited by the water that flowed through them, you have the idea.) Within the cells of the wood, lignin and cellulose were replaced cell-by-cell by minerals, especially silica and quartz, which came out of solution and hardened over time. Since silica plays such an important role, the process that creates petrified wood is often called silicification, and the product can also be referred to as silicified wood.

Turning next to its appearance, the shiny smooth surface of this piece of silicified wood was probably not caused by human hands. The polishing of the piece likely resulted from water rushing by, perhaps in a stream, and shining up its surface, like sea glass or smoothed ocean stones. This wood fossil is not an Island native, and was brought to rest here by the great glaciers that moved across our region in our not-so-distant geologic past.

To be sure, petrified wood is much harder than your average tree. On the Mohr’s scale of hardness, it rates a seven, the same as the mineral quartz. Only a few minerals are harder, including diamonds, rubies, sapphire and topaz.

Petrified wood would also give those minerals a run for their money in comparisons of color. It can exhibit most of the colors of the rainbow, or, more accurately, all of the colors of the minerals. Different chemical forms of iron play a major role in the shades of petrified wood. Black results from iron sulfide or carbon. Hematite, a form of oxidized iron, will cause red or pink fossilized wood; and another hydrated iron oxide, geothite, can also bring on brown, yellow or orange. Green is produced by pure reduced iron. Manganese dioxide makes purple and blue; tan shows its true colors when silica dioxide is present, and white comes out itself when silica is hanging around.

Dig deep; there is no reason to be petrified of what you might find — a special something in the soil; or, in this case, a distinctive dreg in the drag that turned out to be a true ancient treasure.

And while only a small piece was found here on Martha’s Vineyard, it might inspire you to an exploration of the petrified forests of Arizona and California — places so exceptional that they once inspired John Muir to describe them as “a kaleidoscope fashioned by God’s hand.”


Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.