Obsidian monkey effigy jar

Tyler Giles wrote: ‘I have recently come into possession of a solid obsidian monkey effigy jar that strongly resembles some others that are in various museums around the world. Including the texcoco one listed on your site (everything looks identical except for the mouth expression. The trouble is I don’t even know where to begin to verify if this is real, I had a local geologist take a look and he said he was certain it is obsidian but as for someone who could verify the authenticity of something like this, I seem to be at a loss.’