This unusual object came from a local market, where the seller described its origins as "the fellow from Byron". I take it he meant glassblower Colin Heaney of Byron Bay, which is a town nearby. The outer blue iridescence does suggest that source. The item is only roughly ground off at the base, which suggests it may be intended to be part of some larger sculptural work, and that may add to the evidence for a local source. The top is chipped a bit, but whether that made it a second, or that damage happened outside the studio, there is no way to tell.
The oceanic design is cut into the surface, I presume by sandblasting (that being faster and safer than acid, and the edges are sharp).
Why am I asking here? The item is unsigned, but there is a logo included in the design. I cannot figure it out, although one guess was a monogram of the initials LJ. Someone cleverer than me has suggested I should turn it upside down (as in the last photo), where I will see a volcano over the ocean framed by ionic columns (with the sun and moon looking down). That suggests the Mediterranean rather than the east coast of Australia.
Does anyone recognise the logo?
Trevor