One Gem, Three Days to Live

What the geology student wanted, the first time through, was for his roommate to throw away the green stone he had picked up. The roommate called it an emerald. It was uranium mica, and it was giving off enough radiation to kill. The student said so, and the others put him out of the tent, and he froze to death in the open. He wakes up again shortly before graduation, with the stone about to be found. This time he wants nothing to do with it, and he says nothing and watches. The roommate and the friends around him will not give the stone up, and over the days that follow their hair falls out, they cough up blood, and their skin breaks into sores. They accuse the student of conspiring with the professor and the nuclear and chemical defense unit to take the stone from them. He has been recording everything from the start. A laboratory report confirms the dose is lethal and gives them three days. On graduation day the roommate seizes him and holds him as a hostage, meaning to die and take the student with him.