It's about one-and-one-fifth times as heavy as a Deck of Cards.
In other words, the weight of a Deck of Cards is 0.83 times 529 carats.(ISO 216 B8 size, a.k.a. "poker size" 63 x 88 mm, 52-card deck)
A deck of 52 ISO 216 B8-size playing cards weighs 460 carats. Utilizing nearly 3,700 decks, the record-holding largest card tower was built in early 2010, stood over 3.5 m (11 ft), and weighed over 1,100,000 carats.
It's about four-fifths as heavy as a Battery (D).
In other words, 529 carats is 0.804 times the weight of a Battery (D), and the weight of a Battery (D) is 1.24 times that amount.(Alkaline)
A "D" size battery weighs 658 carats. The D size battery is the oldest of the modern battery sizes, first invented by the National Carbon Company in 1898.
It's about three-fourths as heavy as a Baseball.
In other words, 529 carats is 0.74711265969681 times the weight of a Baseball, and the weight of a Baseball is 1.3384862202788 times that amount.(MLB rules)
Per Major League Baseball rules, a baseball must weigh between 690.78947368533 carats and 725.3289473696 carats. A major league pitcher can throw a baseball at up to 150 kph (91 mph) (with a fastball pitch).
It's about two-thirds as heavy as a Billiard Ball.
In other words, 529 carats is 0.66590476190368 times the weight of a Billiard Ball, and the weight of a Billiard Ball is 1.501716247142 times that amount.(American-style, WPA specifications)
Per the World Pool-Billiard Association, a billiard ball weight must weigh between 759.86842105387 carats and 828.9473684224 carats. According to legend, the difficulty in obtaining elephant ivory for the manufacture of billiard balls in the 19th century inspired the search for a replacement material, which led to the development of the first industrial plastic.
It's about two-thirds as heavy as a Puck (Hockey).
In other words, 529 carats is 0.66590476190368 times the weight of a Puck (Hockey), and the weight of a Puck (Hockey) is 1.501716247142 times that amount.(Ice hockey)
A standard ice hockey puck weighs between 759.86842105387 carats and 828.9473684224 carats. Hockey pucks can be shot or passed at speeds of up to 160 kph (99 mph) during games.
It's about one-and-seven-tenths times as heavy as a Battery (C).
In other words, the weight of a Battery (C) is 0.59 times 529 carats.(Alkaline)
A "C" size battery weighs 320 carats. C batteries are typically used in medium-drain devices such as musical instruments.
It's about one-and-nine-tenths times as heavy as a Tennis Ball.
In other words, 529 carats is 1.88 times the weight of a Tennis Ball, and the weight of a Tennis Ball is 0.532 times that amount.(ITF Standard; for Type 2 ball)
Per International Tennis Federation standard, regulation tennis balls must weigh about 281 carats. Competition balls are also tested for bounce height, with the standards requiring that a ball dropped from 254 cm must bounce back to a height of 135 cm to 147 cm.