It's about as heavy as a Grain of Sugar
It's about two times as heavy as a Poppy Seed
In other words, 0.000625 grams is 2.1 times the weight of a Poppy Seed, and the weight of a Poppy Seed is 0.48 times that amount.(Papaver somniferum)
Fifty percent oil by weight, a poppy seed weighs approximately 0.0003 grams. The true pigment of a poppy seed is brown in color, while the characteristic bluish color is an optical illusion caused by a layer of calcium oxalate crystals refracting light rays.
It's about one-fifth as heavy as a Sesame Seed
In other words, 0.000625 grams is 0.172 times the weight of a Sesame Seed, and the weight of a Sesame Seed is 5.81 times that amount.(Sesamum indicum)
A sesame seed weighs approximately 0.00364 grams. The McDonald's Big Mac sandwich, which is well-known for its sesame seed top bun, accounts for the consumption of an estimated 2,010,000 grams of sesame seeds each day.
It's about one-tenth as heavy as a Grain of Sand
In other words, 0.000625 grams is 0.14 times the weight of a Grain of Sand, and the weight of a Grain of Sand is 7.1 times that amount.(medium grain)
With tremendous variety in the size of grain and the component material, grains of sand weigh an average of 0.0044 grams. In 2007, a team of seven in Myrtle Beach created the world's tallest sandcastle, which measured 15.10 m (49.55 ft) in height.
It's about ten-and-a-half times as heavy as a Grain of Salt
In other words, 0.000625 grams is 10.7 times the weight of a Grain of Salt, and the weight of a Grain of Salt is 0.094 times that amount.The mass of a grain of salt is approximately 0.00005850 grams. Salt consumption varies widely by country; the people of the United States consume a combined total of about 57,000,000,000 grams of salt each year.
It's about one-thirty-fifth as heavy as a Grain of Rice
In other words, 0.000625 grams is 0.0 times the weight of a Grain of Rice, and the weight of a Grain of Rice is 33 times that amount.(conventional; US; long-, medium-, and short-gran varieties; uncooked)
With great differences in variety, the average among a sampling of common short-, medium- and long-grain rices finds that a single grain weighs about 0.021 grams before cooking. A staple through most of human history, archaeological evidence indicates that the earliest rice cultivation was about 11,500 years ago.
It's about one-three-hundred-fiftieth as heavy as a Raindrop
In other words, 0.000625 grams is 0.00 times the weight of a Raindrop, and the weight of a Raindrop is 300 times that amount.(a.k.a. drop, a.k.a. droplet) (average)
The weight of a raindrop depends heavily on the type of weather, but averages about 0.20 grams. The familiar teardrop shape of a raindrop is actually an optical illusion, caused by the reflection of the light and the motion of the drop.