Great question! A few crystals commonly associated with mental clarity and focus:
Clear Quartz — known as the "master healer," believed to amplify clarity and cut through mental fog
Amethyst — associated with calming the mind and improving focus, especially good for reducing overthinking
Fluorite — often called the "genius stone," believed to support concentration and clear thinking
Citrine — linked to mental clarity and motivation, a nice one for daytime focus
I personally work with natural gemstones daily, and Amethyst is one I keep coming back to for this purpose — the deep purple tone is also just calming to look at, which helps mentally too. Have a few natural amethyst pieces (earrings, pendants) at armoniagems.com if anyone wants to see what genuine AA+ quality looks like.
Curious what others here find works best for them — mental clarity is such a personal thing with crystals!