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."