Had one dwarf be the recipient of 3 face-palms over the course of a couple years.
1st facepalm: Started my fort without any gem cutting/setting skills in my initial 7, hoping to luck out with immigrants. By the time I was up to 35 dwarves I'd not gotten one, but I did have a rapidly growing stockpile of rough gems and a growing need for trade money. So, after getting 6 more fisherman/mechanics/utterly-utterly-useless dwarves, I decided I'd just grow a Jeweler from scratch. I found a dwarf that had absolutely no skill, but liked a couple different kinds of gems, and set him cutting. Fast forward a few seasons, and guess what I get in an immigrant wave? That's right, a High Master Gem Cutter! *facepalm*
2nd facepalm: Okay, so I have a good cutter, but no setter. Still not a single point of experience in any of my other dwarves, so I took Urist McGemForBrains and set him sorting through the heaps of crappy cut, low value gems to start poorly setting them into the even crappier stone crafts my 3 Legendary Stonecrafters had been spitting out before fey moods had boosted their skills (grumble grumble artifact stone trumpet.. grumble grumble artifact stone earring.. grumble grumble). 3 seasons later, Urist McMasterGemSetter shows up. *facepalm*
3rd facepalm: So, since Urist McGemForBrains had run out his usefulness after wasting the majority of my fortress' gem stock on practise, I punished him by setting him to haul gems by activating Item Hauling and nothing else. I'm cruel, yes, but at least my good Jewelers would never need to leave their post till my fortress was crusted in glittering gemstones. That is till I spotted some gems sticking out of a mountain wall, send my miner up to carve them out, and Urist McGemForBrains becomes Urst McAdvancedWarning by discovering a goblin ambush by way of accidentally getting a goblin sword to the back of his neck. *facepalm*
His Masterwork Marble Coffin was encrusted with Emerald.