The Mortar and Pestle artifact can be found at The Black Gate, in the northern part of Udûn.
Mortar and pestle, possibly of Númenórean Origin, Second Age, circa 3261.
A remarkable find, this artifact may date back to the Second Age, to the great Númenórean incursion wherein the Dark Lord Sauron willingly fell into captivity. It would likely have been used by a healer to grind roots and herbs in the creation of poultices and unguents required to keep an army hale and (relatively) healthy.
"The first messengers have rolled in to camp. They're reporting few casualties. We've struck a mighty blow against the forces of Mordor aligned against us.
Let it be so, and not fools' idle chatter. Hegadorn! What news?
Haha! They say we have won a monumental victory! You'll not be needing all that Athelas you've been grinding, my friend. Few need healing on this day! And more's the wonder! They say the Golden King has brought back a prize - Sauron himself, wearing the heavy chains!"