The short version: a few stones people like to keep within reach while they work — carnelian, clear quartz, tiger eye, citrine, and fluorite. What each one is, and the focus traditions attached to it. Objects and associations, not productivity cures.
Carnelian — an orange chalcedony colored by iron; long a stone of drive and boldness, carried by people facing a daunting task. Shop carnelian
Clear quartz — pure crystalline silica, the clean, classic crystal people keep simply for its clarity. Shop clear quartz
Tiger eye — a golden chatoyant quartz, traditionally a stone of steady focus and resolve. Shop tiger eye
Citrine — sunny golden quartz (mostly heated amethyst); the cheerful stone for a workspace. Shop citrine
Fluorite — banded calcium fluoride in purple and green; collectors keep it for its order and color. Shop fluorite
Pick the one you are drawn to, or see them at a Sedona shop.