Concerning the evolution of her popularity rates over the past thirty years, In March 1998 she reached a record low because she showed no particular emotion when princess Diana died. She was blamed by the nation for her lack of empathy.
At the fiftieth anniversary of her reign, she started being popular again and her popularity literally rocketed for her sixtieth anniversary in the summer of 2012.
Those commemorations are respectively called “Golden Jubilee” and “Diamond Jubilee”.
“Gold” does not oxidize/rust and “Diamond” is unbreakable, it is the hardest stone, it symbolize how precious the British monarchy is and how resistant it can be to the test of time.