The half square triangle unit is probably the most commonly used patch in a quilt block -- well it is second only to the square. It is made simply with two triangles, filling up half the square each -- hence the name. Take a quick look through this website, or in any quilting magazine, and you will start to notice that this half square triangle, regardless of its size, is present in more quilts than not.
Star in Diamond
Free Quilt Block Pattern
I have to say that I can clearly see the diamond in this quilt block, but can't really see a star. But, if you are inventive you might choose to switch up all the colours and a star might just appear in this Star in Diamond quilt block.
All that being said, it is quite a lovely block, with lots of possibilities and is constructed as an uneven nine patch. Also, this would be a good choice to practice up on making those flying geese patches. The flying geese unit is probably the third or fourth most commonly used patch in quiltmaking.
The two sample quilts illustrated give you ideas on setting your blocks side by side in a straight setting, or on point with additional blank blocks to show off your quilting stitches. Once again, there is no limit to the creativity you can experience by adding more blocks, or even an additional colour.