Issued in 2011 to mark the Queen's 85th birthday — not her 90th, which fell in 2016 — this Cook Islands dollar belongs to a category of Commonwealth commemorative coinage that proliferated heavily from the 1990s onward, with smaller Pacific island nations licensing their nominal issuing authority to private mints producing pieces aimed squarely at the collector market rather than circulation.
Issued in 2011 to mark the Queen's 85th birthday — not her 90th, which fell in 2016 — this Cook Islands dollar belongs to a category of Commonwealth commemorative coinage that proliferated heavily from the 1990s onward, with smaller Pacific island nations licensing their nominal issuing authority to private mints producing pieces aimed squarely at the collector market rather than circulation.