Purpleheart, considered a spiritual wood, is also a very durable wood for rings.  The ring above is a simple purple heartwood ring 5mm wide. 

The inset photograph above is a set of purple heart  wood rings with crossed spiraled inlays.  Purple heart wood will turn quite dark over time.   The purpleheart wood rings to the left have narrow spiraled bands of birch wood.  These rings are 4 and 6mm wide respectively.
Purpleheart wood rings
Gallery D
Touch wood rings
TOUCH WOOD RINGS - Wear the warmth of wood.
Wood Rings. Individually custom designed, meticulously hand crafted wooden rings by British Columbia artist and craftsman David Finch.  Touch Wood Rings.  From Canada.
Malia's purpleheart wood ring
purpleheart wood rings with spiraled bands of birch wood
Wooden rings, greyed maple and purple heart wood with crossed spiraled bands