Brownstones occupy a unique place in the New York City psyche, as one of the city’s most prototypical signposts, like yellow cabs and fast walkers, yet are able to stir aching desire and teeth-baring jealousy. Everybody wants one.

Thousands of these structures are crammed into the five boroughs, like sideways stacks of very expensive pancakes. As it turns out, most of them are not only cast from the same mold, but were also made from the same stone, a brown sandstone quarried in Portland, Conn.

After being mined on and off for centuries, the Portland Brownstone Quarries, the very last of a kind, closed down this year, and by the end of this month, the quarry’s final scraps of inventory should be gone.

Preservationists are bemoaning the end of an era, or at least of the chance for a perfect match for the city’s ubiquitous stone. And as Portland’s diamond-studded saws have slowed to their final rest, some stone fabricators have begun to — lovingly, respectfully — hoard the stuff.