I do have to ask meself whether the powers that be have considered the metallic hue of the next jubilee should the Queen attain the age of 106. Have we ever gone beyond platinum? What metals are left? Uranium? Sodium? Lead? Alloy? Woods metal? Einsteinium? This is serious. This woman has staying power. We can't afford to wait until 2031 to crack this one, though that would be the British way...

These are not based on the royal family alone.
A quick check online will tell you:
55th        Emerald        
60th        Diamond        
65th        Sapphire        
70th        Platinum        
75th        Diamond        
80th        Oak
85th        Wine        
90th        Stone        

That is if you were seriously asking. But in view of your comments about the royal family I would guess that you're not really interested in getting an answer.