"This is a small object. While someone might pay you for it, it has no useful abilities of its own." - In-game description
Misc. items are often useless in-game, though some are valuable enough to sell to a merchant.
"These are simple, crude metal tools. They might be useful to a smith or tinker, but not you." - In-game description
Weigh 1.0 lbs.
"This is a precious stone. The serviles on this island value them, and will gladly buy them from you." - In-game description
Gemstones weigh 0.1 lbs. each.