Xorn-Sole Boots
This pair of iron-toed boots is made with the rocky leather hide of a xorn. Each boot is secured with three golden buttons bearing the icon of an eye and has several claw-like spikes extending from its toe and heel. While wearing these boots, you can use a bonus action to speak their command word and click the boots' heels together. If you do, you gain tremorsense out to a range of 30 feet and a burrowing speed equal to your walking speed. If you click your heels together again, you end the effect.
You can use this property for up to 10 minutes, all at once or in several shorter bursts, each one using a minimum of 1 minute from the duration. During this time, you can pinpoint the location of precious metals and stones, such as coins and gems, within the range of your tremorsense.
When the boots' property has been used for a total of 10 minutes, the magic ceases to function until you finish a long rest.
The boss was shocked. For years the underground tavern had been a bastion of secrecy for his network, yet here sat a detective, badge of the city watch worn proudly on her uniform. He didn't catch what she said under her breath as she swung her legs up to rest her heavy boots on his desk, strange, slitted eyes staring at him from the heel of each. He shook himself as she spoke again. "So, you run this place, correct?" Attempting to regain his typical bravado, the boss said, "And so what if I do, lady? My business is an honest one, if a bit private. I swear it's all in order." "What makes you think I was here on business? Maybe I just wanted a friendly chat." "Last lawman to come in here 'not on business' ended up leavin' quiet. If you know what's best, you'll do the same for yourself 'fore it's done for you." The detective smiled. The boss was used to those sorts of smiles, but only from his associates. It was the smile given to prey before its throat is ripped out. "This won't be the last time we meet. I feel it in my soul." And with that, the detective took her feet off the desk and walked out, the boss's guards still too stunned to react properly to her passage. The boss himself was left off-balance; nobody talked to him that way. As she walked back up the stairs and out of the hidden tavern, the detective smiled again. Through her soles she had felt out the compartment hidden within the desk, and the stack of papers inside. The case would be closed before morning.