Wrap and mark a mari using an inconspicuous color wrap and marking thread. Identify the centers of each pentagon in the C10 division so that you can follow the same sequence as you stitch. Using color A (here it's the green pearl cotton) stitch an offset pentagon around each center: the point of the stitched pentagon should be in the middle of the side edge of the marked pentagon (where the "short leg" of the marking intersects the side), and overlap the marking thread just into the adjacent pentagon. Stitch one green pentagon in this manner around all 12 centers. The corners of the pentagons will work in toward the centers of the adjacent pentagons. Using color B (here it's coral), and returning to the same sequence of centers you set up previously (go back to center 1) -stitch a pentagon that has its points half way into the adjacent pentagons around the center you are working. Place the pentagons so tha the corners just overlap into each other (as you did the green ones). The corners of the pentagons will work in toward the centers of the adjacent pentagons. Repeat on all centers following the same sequence you used for stitching the smaller green pentagons.

  This completes a layer (or cycle) - that is, one row on each of the smaller green pentagons and one row on each of the larger coral pentagons. Repeat these layers alternating green and coral (or the colors of your choice) until the points of the larger coral pentagons almost meet at the poles - leave room for one round. Complete one last round on the larger pentagons with a contrasting color, if you desire. I used a darker shade of green on this example. Fill in gaps or spaces as needed - sometimes this is needed if the mari was not accurately round or your marking was off a tad. Groom threads into place with the eye ofyour needle if required.