The Teapot.

Richard hated the teapot. The cracked porcelain body was hideous green while the handle, lid and flared bottom an ugly puce. It was too small and too old to be used but that hadn't dissuaded his wife.
Martha had haggled with the proprietor of the newly opened antique shop, a decrepit man older than he and Martha's mid-sixties, for weeks. Richard had finally intervened when she offered the man a thousand dollars. He had all but shouted at her that they would not be spending that much money on the cracked piece of chintz.
Martha's scornful glare, her normal expression for him, broke when the owner offered Martha the pot for fifty dollars. Along with the stipulation that it returned to him when Martha was done with it.
Martha was too excited and Richard too angry to pay attention to his odd request.
Now it rested on the mantle amongst Martha's crystal duck collection. In the time it had been in their home Martha had become even more obsessed with it. Pointing it out to every visitor and polishing it nearly every day. Richard often desired to crush it under the heel of his shoe.
A week later, as the coroner rolled Martha's body from the house, Richard's eye fell on the little teapot sitting in the floor and he remembered the owner's request.
Richard had come home to find Martha stone dead on their living room floor, teapot clutched in hand.
Richard returned the little pot the next day. The owner offered his sympathies and when Richard asked how he knew he saw the teapot glow red, the cracked porcelain filling in so that it looked brand new.
The smile the owner directed at Richard chilled him to his core and he left the shop and didn't look back.