#### Conversion Factors:

1 troy ounce = 31.1034768 grams

1 pound = 14.5833333 troy oz

1 lượng (Tael) = 37.5 grams

1 pennyweight = 1.55517384 grams

1 ounce = 0.911458333 troy ounce

1 ounce = 28.3495231 grams

1 Troy ounce= 0.829426048 lượng ( làm tròn 8.3 chỉ)

1 lượng (tael) = 1.205652996 Troy Ounce (37.5 grams)

Most popular gold bars: Credit Suisse, Pamp SA, Johnson-Matthey, Heraeus, and Engelhard

#### Why is gold the universal currency throughout human history?

The answer resides in its specific gravity of 19.3. Besides Tungsten (19.35), Plutonium (19.35), Platinum (21.45), there is virtually no other naturally occurring element that can substitute the density of gold. Tungsten will not pass a magnet, and plutonium / platinum are too expensive to be used to fake gold.

For practical purposes, we can just remember that volume of 1 Troy Ounce of gold is 1.61 cm^3. Following is the math:

1 Troy Ounce = 31.1 Grams

Gold (element table ‘AU’) Density = 19.3 grams/centimeter

Volume of 1 Troy Ounce of Gold: X = 31.1 grams/(19.3 gram/cm) = 1.611 cm^3

Example: if a 1-oz 24K gold coin is 2 mm thick, then it’s diameter = square-root(volume / pi / thickness) x 2 = 3.20 cm

Example 2: a 22 carat gold coin (Kruggerand) should have a thickness of .269 cm and a diameter of 3.262 cm= 2.247 cm^3 (volume)

As we can see from the two examples above, there’s a very significant difference between 91.6% gold and 99.9% gold volumes. At the same weight, a 22 carat coin would have 39.5% more volume compared to a 24K one!