Resources not available locally for Smelters houses are
Aluminum,
Amber,
Bronze,
Coal,
Cobalt,
Copper,
Diamonds,
Gold,
Gypsum,
Iron,
Jade,
Obsidian,
Salt,
Stone,
Sulphur,
Local resources for possible trade deals are
Truffles,
Goats,
Gold,
Wool,
Platinum,