Here is the big difference: Star Bites are a larger particle size, about 100-260 microns. This makes them somewhat more sparkly than Sparks! which range from 20-200 microns. They are particularly suited for nail lacquers.
Moon Dusts are a smaller particle size, 30-120 microns, while they are suited for nail lacquers, they are particularly suited for use in eye cosmetics.
California Residents: Warning: This product contains Titanium Dioxide and Silica, crystalline (airborne particles of respirable size) which is [are] known to the State of California to cause cancer and birth defects or reproductive harm. Once the powder is incorporated into a liquid or solid base it can no longer be inhaled and therefore falls off the warning list. For more information go to www.P65Warnings.ca.gov
Warning: this product may contain trace chemicals (<10ppm Lead (Pb); <2ppm Arsenic (As); and <2ppm Mercury (Hg) listed by the State of California under the Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65) as being known to cause cancer, birth defects or other reproductive harm. The level of such chemicals complies with all Federal requirements under the Food, Drug and Cosmetic Act for safety and effectiveness.