The creation, by first-time artist Chris Chamberlain, is entitled Jewel of the Universe and is made up of a third of a million hand-cut pieces of stained glass and 260 carats of natural cut jewels.
Chamberlain spent two-and-a-half years in his garage creating the micro-mosaic, which is painstakingly interpreted from NASA satellite photos and is believed to be the first of its kind.
The world's rivers, including the Thames, Amazon and Nile, are marked out with thousands of tiny pieces of turquoise.
Different jewels indicate over 1,000 cities - including topaz for Belfast, Dublin and Cork, peridot for Derry and amethyst for Limerick.
I can't paint, I can't draw - but I reckon I can cut glass.
Chris Chamberlain, artist
Rubies and emeralds mark spiritual centres like Jerusalem and Mecca, while a non-conflict Kimberley process diamond - the only diamond on the artwork - indicates Freetown, Sierra Leone.
And if the Earth portrait sells, 10% of the profit will go to Ivor Leigh Memorial School near Freetown - a city long associated with blood diamonds.
"For years, I'd had this dream of creatively helping Sierra Leone," Chamberlain said.
"But I struggled for the money to do it. Then one day, divine inspiration struck - why not make a huge artwork about what's probably the best planet in the universe, and try to make it attractive enough that hopefully someone would invest a good amount to own it?
"If I get just a fraction of what I'm asking on eBay, then I can do it ... then I can make a difference to Sierra Leone. And the buyer is welcome to head out there with me and join in.
"Might be the adventure of a lifetime."