Princess Margaret’s oval ruby and diamond ring (Photo: FABRICE COFFRINI/AFP/Getty Images)

July’s birthstone — the classic, vibrant ruby — is a royal favorite, especially when set in gorgeous rings. Above, we’ve got an excellent view at one of several ruby rings from Princess Margaret’s jewelry collection; it sold at Christie’s in 2006 for $550,528. Here’s a look at a few other important royal ruby rings…

Queen Maxima’s ruby and diamond ring (Photo: Michel Porro/Getty Images)

Queen Maxima of the Netherlands often wears a ruby and diamond ring on her right hand. The ring was a gift from her husband, King Willem-Alexander, to mark the birth of their first daughter, Princess Catharina-Amalia (now the Princess of Orange).

Sarah, Duchess of York’s ruby and diamond engagement ring (Photo: Mario Tama/Getty Images)

Sarah, Duchess of York was given a Burmese ruby and diamond cluster ring from Garrard to mark her engagement to Prince Andrew in 1986. Above, she wears it with her gold wedding ring and a gold signet ring. (Interestingly, the photo was taken in 2002, years after her divorce. Sarah doesn’t wear the rings on a regular basis anymore.)

Left: Crown Princess Mary’s original ring (Photo: Scott Barbour/Getty Images); Right, the current ring (Photo: Torsten Laursen/Getty Images)

Crown Princess Mary of Denmark also received a ruby and diamond engagement ring from her husband, Crown Prince Frederik. Initially, the ring included a central diamond flanked by two rubies; later, an additional diamond was added to each side of the ring. The gemstones are meant to echo the colors of the Danish flag.

Princess Marie’s ruby, diamond, and sapphire engagement ring (Photo: Niels Henrik Dam/Getty Images)

Mary’s sister-in-law, Princess Marie of Denmark, was also given an engagement ring with a ruby in its setting. Marie’s ring is a rather literal interpretation of the “flag tribute” idea: it features a ruby, a diamond, and a sapphire, just like the red, white, and blue of the French flag. (Marie may have married a Danish prince, but she was born in France; moreover, that Danish prince is half-French himself.) Several other contemporary royal ladies, including Queen Mathilde of the Belgians and Crown Princess Mette-Marit of Norway, also have engagement rings with rubies.

Crown Princess Mary wears the Danish Ruby Parure (Photo: KELD NAVNTOFT/AFP/Getty Images)

Crown Princess Mary also has another spectacular ruby ring in her jewelry box: the ruby and diamond cluster ring from the magnificent Danish Ruby Parure.