It's about 150,000 times as heavy as a Die (Dice)
In other words, 680 kilograms is 170,000 times the weight of a Die (Dice), and the weight of a Die (Dice) is 0.0000059 times that amount.(for six-sided, 16 mm, rounded cube)
A die, of the size most commonly used in board games and casinos, typically weight 0.0041 kilograms. The use of dice and dice-like tools predates written history, with the oldest known examples belonging to a 5,000-year old backgammon set uncovered during an archaeological dig in modern-day Iran.
It's about one-one-hundred-fifty-thousandth as heavy as The CN Tower
In other words, 680 kilograms is 0.0000057671 times the weight of The CN Tower, and the weight of The CN Tower is 173,400 times that amount.(a.k.a. La Tour CN, a.k.a. Canadian National Tower, a.k.a. Canada's National Tower) (Toronto, Canada)
The CN Tower weighs approximately 117,910,000 kilograms. The Tower is home to the world's highest glass floor — a viewing area that allows visitors to look straight down 342 m (1,120 ft) to the ground below.
It's about 250,000 times as heavy as a Penny
In other words, 680 kilograms is 270,000 times the weight of a Penny, and the weight of a Penny is 0.0000037 times that amount.(United States) (formally one-cent coin) (Union shield design, 2010-present)
The weight of a United States penny is 0.0025 kilograms. According to a 2010 report by the United States Mint, the cost of manufacturing and distributing a penny is $0.0179 — more than its face-value.
It's about one-three-hundred-thousandth as heavy as The Sears Tower
In other words, 680 kilograms is 0.00000337 times the weight of The Sears Tower, and the weight of The Sears Tower is 296,700 times that amount.(officially "Willis Tower" as of 2009) (Chicago, Illinois)
The Willis Tower weighs approximately 201,800,000 kilograms. The outer wall surface of the Tower is covered with black anodized aluminum panels which would total 110,000 sq. m (28 acres) if laid out together.
It's about 400,000 times as heavy as a Playing Card
In other words, 680 kilograms is 380,000 times the weight of a Playing Card, and the weight of a Playing Card is 0.0000026 times that amount.(ISO 216 B8 size, 2.5" x 3.5")
A single ISO 216 B8-size playing card weighs 0.0018 kilograms. Although this size is the most common home playing card, many casinos use "bridge size" cards — 2,640 sq. mm (4.036 sq. in) smaller in area.
It's about one-five-hundred-thousandth as heavy as The Empire State Building
In other words, 680 kilograms is 0.00000205 times the weight of The Empire State Building, and the weight of The Empire State Building is 488,000 times that amount.(New York City, New York)
The Empire State Building weighs approximately 331,000,000 kilograms. About 4% of the building's weight is its 6,000 cu. m (200,000 cu. ft) of limestone façade.
It's about 500,000 times as heavy as a Paper Clip
In other words, 680 kilograms is 490,000 times the weight of a Paper Clip, and the weight of a Paper Clip is 0.0000020 times that amount.(average)
Notwithstanding the tremendous variation in sizes and materials, a typical paperclip weighs about 0.0014 kilograms. The country of Norway has used the paper clip as something of a national symbol since the end of World War II based on the erroneous notion that the paperclip was invented by a Norwegian, Johan Vaaler. However, the paperclip had already been in existence for at least 30 years by the time of Vaaler patented his paperclip design.