The ashes from a flame cremation are primarily the mineral remains from the bone, along with some ash from the cremation box or casket, clothing, and anything else that may have been placed in the process with the body. The ashes from Aquamation are only the mineral remains from the bone, as there are no other materials in the ash.
The colour of ash from a flame process is typically grey in colour. The colour of ash from Aquamation is anywhere from white to a tan colour. With both processes, there can be slight variations in colour from individual to individual.
The consistency of the ash is also different. The ash from flame cremation can have more bone fragments, whereas the ash from Aquamation is a homogenous (consistent) powder. With Aquamation, there's often 20-30% more ash remains returned to the family.