Lieutenant D'Amato, a Human male, was the senior geologist aboard the USS Enterprise serving under Captain James T. Kirk.
In 2268, D'Amato was among the landing party that investigated an ancient Kalandan outpost planet, giving D'Amato the opportunity to explore a planet that was only a couple thousand years old. With this opportunity, D'Amato could possibly make discoveries worthy enough to even startle the Fifth Interstellar Geophysical Conference. Unfortunately his report was never delivered, as D'Amato was soon killed by a projection of the planet's defense system while searching for an underground water source. (TOS: "That Which Survives")
"I haven't seen any evidence that there ever has been any rainfall." (TOS: "That Which Survives")
"Geological disturbances don't frighten me, I've come here to study them, it's my specialty." (TOS: "That Which Survives")
"I'm not afraid." (TOS: "That Which Survives")
"Lucky D'Amato." (TOS: "That Which Survives")
In the Star Trek: Vanguard novel Harbinger, D'Amato's first name is revealed to be Robert. During the course of events in the book, his wife Oriana was killed in action serving on the USS Bombay.
His mirror universe counterpart appeared in the novel The Sorrows of Empire.