This is "TR-11, Phoenix", an advanced-level triangle that I somehow managed to paper piece, and the top diamond was added using my handy-dandy raw-edge machine buttonhole-stitch applique method. The blocks and triangles that involve paper-piecing diamonds often seem to give me a bit of trouble.
This triangle was not fun to make, but it brings me one step closer to the end of the top row. It's a good thing that I love the way the triangles look with the quilt...