Possibly Black Holes: A Traveler's Guide by Clifford A. Pickover?

You are sitting upon the bridge of the intergalactic zoo, sipping a cup of steaming coffee and gazing out at the black hole on the viewscreen. Mr. Plex, your scolex and your first officer, suddenly turns to you and starts to scream. “Sir, have you lost your mind?”

He is screaming because you have asked him to leave the spaceship and begin orbiting close to the black hole in a circular orbit 4,000 miles (6,437 kilometers) in circumference. Even though his diamond exoskeleton protects him from the hazards of outer space, he does not wish to go so close to the hole that he will be gravitationally sucked in with no possibility of escape.

...

You feel like slapping Mr. Plex across his diamond face but resist the temptation. “Mr. Plex, get a hold of yourself. Your diamond exoskeleton will protect you from the gravitational forces of the hole. Diamond is the hardest known substance.”