It's about as heavy as a Football (Soccer).
(a.k.a. Soccer, a.k.a. Association Football) (FIFA Law 2 specification)
According to FIFA's Law of the Game number 2, a football must weigh between 260 pennyweights and 290 pennyweights. An artifact on display at the Smith Art Gallery in Museum in Stirling, Scotland is said to be the world's oldest football and is about one-third to one-half the size of a modern football.
It's about one-and-one-tenth times as heavy as a Football (American).
In other words, 290 pennyweights is 1.097142857143 times the weight of a Football (American), and the weight of a Football (American) is 0.9114583333332 times that amount.(a.k.a. "pigskin") (NFL standard)
Per National Football League official rules, an American football must weigh between 255.2083333333 pennyweights and 273.4375 pennyweights. Because of NFL regulations, ceremonial considerations, and backup requirements, each NFL Superbowl requires the manufacture of 144 balls exclusively for the event.
It's about one-and-three-tenths times as heavy as a Can of Soup.
In other words, the weight of a Can of Soup is 0.77 times 290 pennyweights.(for Campbell''s Condensed Tomato Soup, 317.9 ml)
A can of Campbell''s Tomato Soup weighs 230 pennyweights. Cans have been used to store soup and other foods since their invention in 1913, but a dedicated can opener was not developed until cans began to use thinner materials — prior to that time, cans were usually opened using various blunt instruments and tools.
It's about seven-tenths as heavy as a Basketball.
In other words, 290 pennyweights is 0.72311688312 times the weight of a Basketball, and the weight of a Basketball is 1.3829022988 times that amount.(NBA official ball standards, Size 7)
A regulation NBA basketball, manufactured by Spalding, is known as a Size 7 ball and weighs 401.04166667 pennyweights. These balls have 4,118 pebbles each with a diameter of 2.5 mm
It's about one-and-a-half times as heavy as a Human Heart.
It's about two times as heavy as a Hamster.
In other words, the weight of a Hamster is 0.5 times 290 pennyweights.(for Syrian hamster, a.k.a. golden hamster, a.k.a. Mesocricetus auratus; adult)
An adult Syrian hamster has a typical weight of about 100 pennyweights. Known for transporting food in the pouches of their cheeks so that they can bury it later, some hamsters can store up to 20,000 pennyweights of food in their borrows.
It's about half as heavy as a liter of Water.
In other words, 290 pennyweights is 0.4509878 times the weight of a liter of Water, and the weight of a liter of Water is 2.217355 times that amount.(fresh; 4° C / 39.2° F; maximum density)
Contrary to popular belief, 1 liter (0.0.264172052358148 gal) of water at 4° C / 39.2° F (its point of maximum density) weighs 643.0329 pennyweights rather than 1 kg exactly. The total volume of water on the planet Earth is about 13,590,000,000,000,000,000 (13.59 quntillion) L (3,590,000,000,000,000,000 gallons).