Diamond standing on the left, three Fat-tiles fanning right, the black negative space between them reads as K. Symmetric across the horizontal.
No drawn line needed — the K is the space between the tiles.
Your favourite: the unit circle, radii from centre, and the 5th vertex marked (bottom-left) — no line attached; it's the leg that relaxes and drops into place when it rolls in.
Just the coin, K embossed/pressed into it — larger circle, glossy.
True gold Fat-tiles; the Diamond in blue, deep green, or wood-brown. Metallics next if you like.