This is the Orchids of Hawaii R-13A Coconut mug. The exterior surface is brown with a bisque finish. The interior is glazed and white.
On the bottom of this 15 ounce ceramic mug is “Orchids of Hawaii”, “R-13A”, and “Japan”.
Other coconut mugs in my collection include the Dynasty Wholesale DW116-S Coconut mug.
Many variations of the coconut mug can be found on pages 108-112 of Tiki Quest - Collecting the Exotic Past by Duke Carter.
While coconuts are often associated with Polynesia, there is controversy as to their actual origin. Some contend the coconut palm originated in southeast Asia while others argue it came from south America. Without a doubt, its distribution across Polynesia was aided by the seafaring Polynesians who used the tree as a source of food and building materials.
Drinks served in coconuts, whether real or ceramic, are a staple of classic Polynesian restaurants and Tiki bars.