Finally, a gold standard produces trust in the dollar because gold has the unique characteristic of maintaining its buying power over time.

FORBES: The Dollar, Gold And The Quality Of Money

Meantime, a unique characteristic of this GL, practically worth the price of admission all its own, is its serene, even ceremonial, quiet.

WSJ: 2013 Mercedes-Benz GL350 BlueTec Review: A Quiet-Tuned Land Megayacht | Rumble Seat by Dan Neil

They're trying to figure out whether the problems with torcetrapib come from lowering HDL cholesterol, lowering a particular type of HDL cholesterol, or from some unique characteristic of the torcetrapib molecule itself.

NPR: Deaths Prompted Withdrawal of Cholesterol Drug

Plate tectonics, the formation of faults and the moving of the continental crust over a molten interior, is a characteristic unique to Earth and it meant that minerals evolved far beyond those on any other planet in the Solar System.

ECONOMIST: Minerals