This is VeeGum T, a processed Hectorite clay (similar to bentonite, extremely small particle size). I have propeller-mixed enough powder into water that it has begun to gel. How long does it take for them to begin to settle? Never. This sat for a month with no visible change! That means it is colloidal.
In ceramics some clays of are of such exceedingly small particle sizes that they can stay in suspension in water indefinitely. But unlike common colloids, clays have a secret weapon.