Sapphires
Her eyes, the day he sees her for the first time, are blue, so blue, blue as sapphires.
Later, he understands that it was a spell, it was a joke, it was a dare for the first day of Hogwarts.
But nevertheless, that is the color he will always associate with Marlene.
Sapphire.
When he gets her a ring (she protests and says she will never, ever, marry, she wants to be young and beautiful and untied down until she dies [she wants to die young,] and he says it wasn't an engagement ring anyway, don't be so full of yourself, Marlene Mckinnon [only it sort of was]) it has a sapphire in it.
She asks him why on earth he bought her such a wimpy colored stone, and couldn't he have chosen rubies or onyxes or something like that?
He laughs it off and pretends it doesn't hurt when he sees the ring lying unworn at the bottom of her drawer, years later, after she's gone.
But somewhere, deep inside, a part of him bleeds for the little girl with the spell-colored eyes and the red-gold hair that he saw on Platform Nine and Three Quarters, all those years ago.