Large Natural Corundum

[hemamipo]

I have been asked by a contact of mine to sell a large natural corundum ruby. Here are the specs:

Description: 1 rough stone
Species: Natural Corundum
Variety: Ruby
Origin: None
Total Weight: 469.18 ct
Shape: Rough
Cut: Rough
Measurements: 51.8 * 38.4 * 39.2 mm
Transparency: Translucent to opaque
Color: Purplish red
Comments: No indication of thermal enhancement
As per rough shape permits


What is the best way to go about selling this stone within a reasonable timescale?
Any information would be welcome.