Gold can still be found in the Bendigo area.
On Mothers' Day 2019, a family out walking Lucky their dog on the outskirts of Bendigo walked onto a gold nugget. They took it along to the local IGA supermarket to weigh it. The gold nugget weighed 624 grams (about 20 ounces).
Today, the price of gold in Australia is listed as $65.76 per gram. So, if pure, the gold in this nugget would be worth 624 × $65.76 ≈ $41,000.
How big would this gold nugget be?
We know the mass of the nugget is 624 grams.
We can look up the density of gold in tables, ρ = 19.3 g cm-3
Since density = mass (g) ÷ volume (cm3)
19.3 = 624 ÷ volume (cm3)
volume (cm3) = 624 g ÷ 19.3 g cm-3 = 32.3 cm3
Which could be represented by a cube approximately 3.2 cm × 3.2 cm × 3.2 cm
Not very big at all is it!
Ballarat, another Victorian Gold Rush town and site of the historic "Eureka Stockade", was also the place where another spectacular gold nugget was found in June 2019 (and reported nationally in July 2019). This gold nugget weighed about 2 kilograms, or 2,000 grams.
At today's prices, it would have a value of about 2,000 × $65.76 ≈ $130,000
And how big would this nugget be?
density = mass (g) ÷ volume (cm3) volume (cm3)
density = mass (g) ÷ density (g cm-3) = 2,000 g ÷ 19.3 g cm-3 = 103.6 cm3
The dimensions of a cube with this volume would be about 4.7 cm × 4.7 cm × 4.7 cm
Which would fit nicely into the palm of your hand as shown in the photograph below
Further Reading:
Density Calculations
Suggested Study Questions:
- The density of gold is 19.3 g cm-3. Calculate the mass of
- 1 cm3 of gold
- 10 cm3 of gold
- 1 m3 of gold
- The density of gold is 19.3 g cm-3. Calculate the volume of
- 1 g of gold
- 10 g of gold
- 1 kg of gold
- The density of gold is 19.3 g cm-3. Calculate the dimensions of a cube of gold which has a mass of
- 5 g
- 500 g
- 5 kg
- The density of gold is 19.3 g cm-3. Calculate the diameter of a sphere of gold which has a mass of
- 2 g
- 200 g
- 2 kg
- A credit card has the approximate dimensions 65 mm × 55 mm × 1 mm. Calculate:
- volume of the credit card in cm3
- mass of a gold credit card
- value of a gold credit card if the cost of gold is $65 per gram
- Why aren't "gold" credit cards really made out of gold?
- Gold is one of the few metals that is found in nature as the "native" element (that is, it is found as the element and not in compounds). Explain why gold can be found in nuggets.
- Name some other metals that can also be found in their native state (that is, found as the element and not as compounds). Explain why these metals can be found in their native state.
- Name a metal that is not found on Earth in its native state, and explain why it is not found in nature as the uncombined element.
