My pizza stone is bust!
And I'd only had it about 30 years!
Just these past few weeks I'd started using it again, and cranking the oven up to Volcano Heat (545°F, rather than the wimpy 450°F or thereabouts I'd used in the past), and on this occasion, after depositing the pizza on it, I left the oven door open for a good fraction of a minute while retrieving an errant mushroom (which process didn't do my arm hair a lot of good). All seemed well, but when I returned a few minutes later to claim the cooked pizza, the stone was as shown here (but still topped with a small pizza, with mushrooms, olives, and prosciutto).
Oh, well. I've come to regard the pizza stone as Essential Cookware, so it's time to fork over $30 from my already depleted treasury for a bigger, heavier model that gets good reviews on Amazon. Might use it for various sorts of non-pizza bread, too, if I get inspired.
One of these years, I'll build myself a proper pizza oven. The wood-fired kind.