Emperor's Laurel Crown Quest
This is a guide to make:
1.) Find NPC Baron at blacksmith guild located
2.) Walk up 2 flights of stairs to reach Baron and the other NPC to make counteragent & mixture.
3.) Next he'll ask you to look around the room. Inspect the crack in the corner nearby.
4.) Once you've spoken to Baron again. He'll need you to find the Thief who escaped through the crack. Find the Thief located at:
Warning: once you confront him, several wild roses will spawn to attack you. They're easy enough to kill though.
5.) Once you've defeated the wild roses. Talk to the Thief again and he'll give you the crown he stole. Then go back to Baron. He'll comment how light it is and asks you to find a Jeweler in Alberta to appraise it.
6.) To appraise the crown he'll ask you to bring him the following items:
To make a welding mask follow the guide on RMS here: 
7.) Once you bring the Jeweler the ingredients. He'll ask you to wait. Wait for 10 minutes and he'll appraise the crown as fake.
8.) Go back to Baron and he'll tell you to find and confront the Thief again.
9.) Go back to the Thief. He'll teleport away from you when you confront him. He's moved to another spot located at
Careful once you confront him again he'll spawn more wild roses. When you've defeated the monsters talk to Thief who will hand you the real crown.
10.) Bring the real crown back to Baron
11.) To make sure it's real, have it appraised by the Jeweler in Alberta who will just ask for 200,000 zeny, not the ingredients again.
12.) Wait another 10 minutes and Jeweler will confirm it's real.
13.) Take the crown back to Baron and he'll ask you to find glue and aluminium to fix it.
14.)To find the glue warp to Brasilis and find Drop Machine at:
15.) To find the aluminium. Warp to Einbech Dungeon and talk to the Miner at:
He'll trade 5 aluminium for 100 Jellopies. 16.) Once you have both of the items take them back to Baron and he'll ask you to deliver it to the Maid at Prontera Castle.
The maid it located at the further northern room where the King is. She's towards the right throne.
17.) Finally go back to Baron
To make the crown you need to bring him:
- 2x gold
- 100x Iron
- 10x Oridecon
- 20x Elunium
- 50x Steel
- 1x 3carat diamond
- 1 million zeny
Credits to themadkez for the guide.