The gram is a unit of mass in the International System of Units (SI) equal to one thousandth of a kilogram.
The mass of this pen cap is about 1 gram. A weight scale such as this can give an accurate reading of mass for many objects (see Weight vs. mass).
One gram of amphetamines (the unit often used for street retail)
A container of Wellcome-brand cocaine, containing 1 ounce or 28.3 grams (note the non-standard abbreviation gm.).
International System of Units
The International System of Units, internationally known by the abbreviation SI, is the modern form of the metric system and the world's most widely used system of measurement. Coordinated by the International Bureau of Weights and Measures it is the only system of measurement with an official status in nearly every country in the world, employed in science, technology, industry, and everyday commerce.
Silicon sphere for the Avogadro project used for measuring the Avogadro constant to a relative standard uncertainty of 2×10−8 or less, held by Achim Leistner
Stone marking the Austro-Hungarian/Italian border at Pontebba displaying myriametres, a unit of 10 km used in Central Europe in the 19th century (but since deprecated)
Closeup of the National Prototype Metre, serial number 27, allocated to the United States