Six weeks ago suffered small chip fracture on big toe. little pain now, but small hard lump present that rubs. should i be concerned?

This may get better!: Though it's been six weeks, it is still a bit early in the overall healing process. The small hard lump you describe may be a soft tissue reaction related to the fracture. Hopefully, it is not the bone itself that has healed with prominence. The former will improve over time. The latter will remain and might require a small surgical procedure to remove this bone prominence in the future as needed.

Toe injury: The lump could be a congealed blood clot under the skin of the big toe. Warm soaks may help break it down. See a podiatrist if the discomfort and lump persist.