Purchsed from Mefert's 2007.
(plastic, 2.5 inches between faces, 4 inches point to point,
opposite faces are light blue / blue, yellow / white, green / light green, red / orange)

Rotation is not about the points of the diamond; rather it is along each of the four planes that cuts the puzzle in half. This puzzle is a variation of the Skewb (it is a smaller version of the Super Skewb Diamond). Jaap's Page presents a solution that is a bit more efficient that applying his solution for the Skewb.

Further Reading
Meffert's Page, from: http://www.mefferts.com/puzzles/solution-skewb-diamond1.html
Jaap's Page, from: http://www.jaapsch.net/puzzles/diamond.htm