It's about 350,000 times as heavy as a Quarter
In other words, 31,000,000 grains is 354,300 times the weight of a Quarter, and the weight of a Quarter is 0.0000028220 times that amount.(United States quarter-dollar coin) (a.k.a. Quarter dollar, a.k.a. America the Beautiful quarter, a.k.a. two bits)
The America the Beautiful series quarters, which began to enter circulation in 2017, weigh 87.50 grains each. In answer to the common riddle, there are 119 ridges around the edge of the coin in its current design.
It's about one-four-hundred-thousandth as heavy as The Golden Gate Bridge
In other words, 31,000,000 grains is 0.00000250 times the weight of The Golden Gate Bridge, and the weight of The Golden Gate Bridge is 400,000 times that amount.(San Francisco, California and Marin County, California) (Post 1986 weight reduction; total weight of bridge, anchorage, and approaches)
Following the completion of the 1986 project to eliminate excess material, the total weight of the Golden Gate Bridge — including its anchorages and approaches — is 12,400,000,000,000 grains. The two main cables in the spanning the bridge are spun out of a total of 129,000 km (80,200 mi) of wire.
It's about 400,000 times as heavy as a sheet of Paper
In other words, the weight of a sheet of Paper is 0.00000250 times 31,000,000 grains.(for US Letter, a.k.a. ANSI A; 215.9mm by 279.4mm (8.5 in x 11 in); 20lb)
The weight of a ream (500 sheets) of 140,000 grains, 8.5 inch x 11 inch paper is 31,000 grains, each sheet weighing 77 grains. Paper of this size has a thickness of 0.004 caliper (0.1 mm).
It's about 500,000 times as heavy as a Die (Dice)
In other words, the weight of a Die (Dice) is 0.00000200 times 31,000,000 grains.(for six-sided, 16 mm, rounded cube)
A die, of the size most commonly used in board games and casinos, typically weight 63 grains. 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 800,000 times as heavy as a Penny
In other words, the weight of a Penny is 0.00000130 times 31,000,000 grains.(United States) (formally one-cent coin) (Union shield design, 2010-present)
The weight of a United States penny is 39 grains. 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 1,000,000 times as heavy as a Playing Card
In other words, 31,000,000 grains is 1,100,000 times the weight of a Playing Card, and the weight of a Playing Card is 0.000000910 times that amount.(ISO 216 B8 size, 2.5" x 3.5")
A single ISO 216 B8-size playing card weighs 28 grains. 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 1,500,000 times as heavy as a Paper Clip
In other words, the weight of a Paper Clip is 0.000000710 times 31,000,000 grains.(average)
Notwithstanding the tremendous variation in sizes and materials, a typical paperclip weighs about 22 grains. 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.