|The Jardine Star Brooch|
"In 1981 the Queen was left a late-Victorian diamond star brooch by Lady Jardine, which she has worn on many occasions. It has a collet diamond on a knife-wire between each of its eight points."
Further detail on Lady Jardine and what her connection or motivation might have been to gift the Queen with this brooch is omitted. There are a few Jardine Baronetcies and the wives of the baronets would be titled Lady Jardine, but which Lady Jardine is referenced here is unclear. A queen receiving a bequest of jewels from someone no matter the connection is not so unusual, of course; one example is the Greville bequest which provided many of the Queen Mother's favorite jewels.
The brooch in action, as the Queen addresses Parliament on the occasion of her Diamond JubileePrincess Anne owns a similiar piece, and there are plenty more star brooches out there that look like this one. Their all-purpose design never really goes out of style, as the Queen shows us regularly.