Okay, so… I'm just going to write out a famous head-canon… Okay?
Sam felt his heart break as the amulet hit the bottom of the bucket. He felt a sting of betrayal. A dagger slicing across his soul.
Dean had carried that piece of jewelry for so long, it was basically a part of him. And now he just abandoned it? Because it didn't have the right powers? Because it didn't have the powers they hadn't known of in the first place?
Sam watched his brother walk out the door, without looking back. Without second doubts when it came to the amulet…
Tears stung in his eyes, he wanted to yell at Dean. He wanted to tell his brother to pick it up from the trash can…
But…
Dean didn't have to know…
On his way out, Sam stopped by the trash can. Knelt down, and fished the old amulet out. He had to do it, it was the only acceptable thing to do…
He would give it back to Dean. In time, Dean would grow to miss it… And one day… He would love it just as much again… Sam just had to wait for Dean to get there…
Okay. Hope you liked it…