Dilatent fluids have a viscosity that increases as the shear rate increases. Examples are moist sand, quick-sand, heavy starch suspensions, many honeys—buckwheat, sumac, orange, tarweed, Hawaiian Honeydew, etc.
Thixiotropic fluids become more fluid, viscosity decreases, with time as they are stirred. Although extensive experimental data are not available, the time function seems to be logarithmic. When motion stops, the fluid will return to its original viscosity although a hysteresis may be formed on the return. Bread dough, heather honey, some soil suspensions, certain paints are examples.
Rheopetic fluids exhibit an opposite effect to thixiotropic fluids because they become less fluid with time. Otherwise, the characteristics are comparable