
It's about ninetenths as heavy as a Tennis Ball.
In other words, 260 carats is 0.925 times the weight of a Tennis Ball, and the weight of a Tennis Ball is 1.08 times that amount.
(ITF Standard; for Type 2 ball)
It's about oneandonefifth times as heavy as a Golf Ball.
In other words, 260 carats is 1.162 times the weight of a Golf Ball, and the weight of a Golf Ball is 0.8606 times that amount.
(per R&A USGA Rules of Golf; maximum rule weight)According to the Rules of Golf (as approved by the United States Golf Association and the Rules Committee of the Royal and Ancient Golf Club of Saint Andrews), golf balls must weigh no more than 223.8 carats. Golf balls are not required to have the familiar dimpled pattern, but the design has been popular since its invention in 1905 because it reduces drag while increasing lift.
It's about fourfifths as heavy as a Battery (C).
In other words, 260 carats is 0.82 times the weight of a Battery (C), and the weight of a Battery (C) is 1.2 times that amount.
(Alkaline)
It's about oneandthreefifths times as heavy as a Light Bulb.
In other words, the weight of a Light Bulb is 0.63 times 260 carats.
(a.k.a. lamp) (for A19size, 60w, incandescent bulb by Bulbrite; package weight)
It's about threefifths as heavy as a Deck of Cards.
In other words, 260 carats is 0.57 times the weight of a Deck of Cards, and the weight of a Deck of Cards is 1.8 times that amount.
(ISO 216 B8 size, a.k.a. "poker size" 63 x 88 mm, 52card deck)
It's about two times as heavy as a Battery (AA).
In other words, 260 carats is 2.2 times the weight of a Battery (AA), and the weight of a Battery (AA) is 0.45 times that amount.
(Alkaline)
It's about twoandahalf times as heavy as a Mouse.
In other words, the weight of a Mouse is 0.4 times 260 carats.
(a.k.a. "House mouse", Mus musculus) (adult) 
