The Diamond Symbol meaning from a Native American Indian perspective includes several aspects.
The diamond motif is seen in butterfly symbolism, where it represents the concept of transformation and immortality. I’ve written about the Native perspective on the diamond butterfly (including an actual image of the motif) here.
The diamond symbol is also seen from the Osage as a representation of the earth. It will have a equa-distant cross in the center indicating the importance of the four cardinal winds/directions.
The diamond shape is also symbolic of protection in the form of the wind. I’ve written about the Native American symbol for wind here.
Also a symbol of life in the Native perspective, each side is a facet of life’s learning phases:
Other more in-depth information can be found here: