A ruby can be heated into beauty, however, It cannot be heated into value

The majority of rubies on the market have been heated, typically between 1,200 and 1,800 degrees Celsius to improve color saturation and dissolve inclusions. Heated rubies are widely accepted in the trade and accessible but command a fraction of the price of an unheated equivalent. "No indications of heating" on a GRS or Gübelin laboratory report is the designation that changes EVERYTHING.

At significant carat weight, the price differential between a heated and unheated ruby is not marginal,  it is the sliding door moment between a beautiful stone and an investment-grade asset. Without an independent Swiss laboratory report confirming treatment status, you cannot know what you are actually acquiring. 

An unheated Burmese ruby with a GRS or pigeon blood designation is among the rarest colored stones on earth. Most of what is sold as fine ruby at retail is not in the same category.