Measure the mass of the gold object on the scale. Record the mass in grams (g).
Pour water into a graduated cylinder until the cylinder is approximately half full. Record the water level in cubic centimeters (cc), being careful to read the bottom of the meniscus (the curved shape of the surface of the water). Let this water level measurement be referred to as the initial volume, or "Vi." Note that 1 milliliter (ml), which is a common volume unit used on the graduated cylinder, is equivalent to 1 cc.
Carefully lower the gold object into the cylinder. Ensure that no water is splashed from the cylinder as this will result in an inaccurate reading.
Record the water level in the cylinder with the gold object submerged. Let this volume reading (measured in cc) be referred to as the final volume, or "Vf."
Calculate the difference in water levels before and after submerging the object. For example, the difference = Vf - Vi.
Divide the mass of the object by its volume to yield the density of the object. For example, the object density = mass / (Vf -- Vi). Compare the measured density to that of pure gold (19.3 g/cc) to determine whether the object is made of pure gold.