A post from Ming
Volume – is the unit of space occupy by a given object. Any object (solid, liquid, gas) that occupy space has a volume. A regularly shape object whose thickness is 1 centimeter(cm) , whose width is 1 cm , and whose length is 1 cm has 1 cubic centimeter(cc) volume; or 1cm x 1cm x 1cm = 1 cubic centimeter (cc). On the other hand, a 1meter(m) x 1m x 1m object has a 1 cubic meter(cM) volume.
Can you imagine how big is 1cm x 1cm x 1cm or one cubic centimeter(cc) of water? By the way, 1 inch is approximately 2.54 centimeters(cm). Density – is the weight per unit volume of an object. At 4°C, one cubic centimeter (cc) of water (1cm x 1cm x 1cm) or one milliliter (mL), weights 1 gram. Therefore the density of water is 1gram per cubic centimeter(cc).
One liter is 1,000 cubic centimeter(cc), therefore, one liter(L) of water weights approximately 1 kilo because there are 1000 grams in one kilo. Therefore one cubic meter of fresh water weights 1 ton!!!
Now do you know how heavy is one cubic centimeter(cc) (1cm x 1cm x 1cm) of pure gold is? One cubic centimeter of pure gold weights 19.32 grams!!! Gold is 19.32 times heavier than equal volulme of water.
The same volume of Platinum weights 21.45_grams!!! The term specific gravity is used to describe the weight or density of an object compared to an equal volume of fresh water at 4°C (39° F).
Water has an specific gravity of 1(one). Any object whose specific gravity is less than one is lighter than water and will therefore float on water, and any object whose specific gravity is greater than one(1) will sink in water. From above, we can say that pure gold is 19.32 times heavier than an equal volume of water and therefore gold has a specific gravity of 19.32. Densities and Specific Gravity of some common metals and water:
Element----------Density --------Specific Gravity
------------------grams/cc
1. Water.................1.00................……1.00
2. Aluminum.......…2.70...............……2.00
3. Iron.................….7.87...............…….7.87
4. Nickel.............…..8.90...............……8.90
5. Copper............….9.96................……9.96
6. Silver.................10.50..............…...10.50
7. Lead...............….11.35...............…..11.35
8. Palladium.......….12.02...............….12.02
9. Gold...............…..19.32................….19.32
10. Platinum.......….21.45...............….21.45
Application:
A. It is impossible to use iron, nickel, copper or silver to fake a gold, or platinum!!! Why?
Because: 1) To fake one cubic centimeter(cc) volume of gold (1cm x 1cm x 1cm) with gold plated iron, nickel or silver, your final product will only weights about 10 grams because either iron, nickel or copper has a density of just about 10grams per cc which is only half the density of pure gold which is about 19 grams per cc.
On the other hand: 2) To fake a one kilo of gold using gold plated iron, nickel or silver, your final product volume will be already 100 cc which is already two times larger than the volume of pure gold should be, which would be just about 50 cc, for the same reason that the density or specific gravity of gold is about two times heavier than those of iron, nickel or silver.
B. The volume of water spilled or displaced if you immersed an irregular object say gold or platinum in a water filled container is equal to the volume of the object. To determine that, you can either weights the displaced water with a weighting scale, and since you know that 1 cubic centimeter(cc) water weights 1 gram, then if the spilled water weights 50 grams then its volume is 50 cubic centimeter(cc) and that is the volume of the object.
On the other hand, if you don’t have a weighting scale but have a graduated cylinder instead, then you can measures the volume of the spilled water in cubic centimeter(cc) or milliliters(mL) directly and that will be the volume of the object you have immersed in the water.
GOLD PROPERTIES Metal Density
Gold 19.3
Silver 10.5
Platinum 21.4
Palladium 12.0
Copper 9.0
GOLD
9ct 10.9 to 12.7
14ct 12.9 to 14.6
18ct Yellow 15.2 to 15.9
18ct White 14.7 to 16.9
22ct 17.7 to 17.8
Sterling Silver 10.2 to 10.3 950
Platinum 20.1
Other Facts about Gold Weight
It follows from the above table that:-
• A cubic centimetre of gold will weighs 19.3 grams.
• A cubic meter of gold will weighs 19.3 tonnes.
• A cubic inch of gold will weighs 315.2 grams = 10.13 troy ounces = 11.06 avoirdupois (ordinary) ounces.
• A cubic foot of gold will weighs 545.225 kilos = 1188.6 pounds (avoirdupois).
QUICK GOLD TESTING:
1. Use 80% Aqua Regia / Cyanide Solution. This dissolves Gold and Platinum.
2. Use Water Displacement Method: MATERIALS NEEDED
-water container with hole for overflow
-calibrated beaker in cubic centimeter cc (to catch overflow for calibration)
-weighing scale in grams gms (for weighing the overflow, if beaker not calibrated)
PROCEDURES -
-weigh the reputed gold in grams -use water displacement method to find the volume (water density 1 gms/cc) -calculate au 19.32 gms/cc x volume(water displaced), (unit in grams)
-the result should be equal or little less equal to the reputed gold depending on karat rating.
A 4”x4”x16” 24k gold should weigh 81,049 grams (convert the 256 cubic inches to cubic centimeter equals 4,195.09.
Multiply this to gold spec. gravity of 19.32 gms/cc, the answer is 81,049 grams.
Where- as the same size gold bar in 22k will give only 74,500 grams only.
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