While you're wearing this austere stone circlet, you have proficiency with mason's tools, and whenever you make an Intelligence (History) check related to the origin of stonework, you are considered proficient in the History skill and add double your proficiency bonus to the check, instead of your normal proficiency bonus.

In addition, you can use your action and speak the circlet's command word to gain tremorsense that extends out to a range of 60 feet for 10 minutes or until your concentration ends (as if concentrating on a spell). If you are a dwarf, the range is doubled and the effect lasts for up to 1 hour instead of 10 minutes. The circlet can't be used in this way again until the next dawn.

Notes: Twice Proficiency: Ability Checks, Sense: Tremorsense, Scrying, Exploration, Headwear