Siliceous Oozes acrylic on wood 7.375x5.25 (no longer exists)
Pulling from my geology classes at William & Mary here. I was always a big fan of the term siliceous oozes. It describes a situation where microscopic critters like diatoms accumulate on the ocean floor when the water is nearly saturated with silica. Very slowly blankets of a silica-rich ooze are formed. If I remember correctly, these oozes later become chert after spending a few million years in nature's pressure cooker. Chert's cool because you can make cutting tools and arrowheads out of it. I like chert.
I've included an image to show the scale - a good trick for photographing an outcrop or rock. I reckon it's just as useful photographing artwork. I'll try to make a habit out of it. The Nikon cap measures 2.125 inches in diameter, so this one is a little guy.