From Fellowship of the Ring:
P315 - Boromir - "And seated a little apart was a
tall man with a fair and noble face, dark-haired and grey-eyed, proud
and stern of glance.
"He was cloaked and booted as if for a journey on horse-back; and
indeed though his garments were rich, and his cloak was lined with fur,
they were stained with long travel. He had a collar of silver in which
a single white stone was set; his locks were shorn about his shoulders.
On a baldric he wore a great horn tipped with silver that now was laid
upon his knees."