immersion
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Identifying Yellow Sapphire Using the Blue Filter
- Date: 2005-10-01
 
                    
                                                                                            
                        Introducing the blue filter as a gemological tool to separate natural and Verneuil synthetic yellow sapphires.
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Padparadscha or Pretender — An Unusual Pink-Orange Sapphire
- Date: 2016-06-01
 
                    
                                                                                            
                        An orangish pink “padparadscha” sapphire was submitted for testing at Lotus Gemology’s Bangkok laboratory. Testing showed a number of conflicting features that suggested the gem was a cleverly treated synthetic pink sapphire designed to imitate natural padparadscha.
 
