By American standards, fake gold is anything less than 10 karats. If you're wondering if your gold is real, the most reliable way to find out is to take it to a certified jeweler and have it tested. If you want to check for yourself, use these instructions to make that determination.Know More
Gold isn't a magnetic metal, so if it pulls towards or sticks to the magnet, it's fake. However, just because it does not react to the magnet does not mean it's real, as non-magnetic metals are used in counterfeit pieces as well.
A stamp indicates fineness (1-999 or 0.1-0.999) or karat (10K, 14K, 18K, 22K or 24K). A magnifying glass makes this easier to see. An older piece might not have a visible marking due to wear. Counterfeit pieces often have a marking that appears authentic; more testing may be needed either way.
It's important to check for discoloration in areas that face constant friction, typically around the edges. If the gold seems to be wearing off and showing a different metal beneath, you probably have a piece that is only gold plated.
The Molisch test is used to detect carbohydrates.The test can also be used to identify compounds that can be dehydrated to furfural in the presence of sulfuric acid.Full Answer >
The Jominy end quench test is used to measure the hardenability of steels. Hardenability differs from hardness in that it is a measure of steel's ability to be hardened to a particular depth rather than a measure of its stability under load.Full Answer >
Seliwanoff's test is a chemical test that is performed to differentiate between a ketone hexose and aldehyde sugar. The test is named after the chemist who developed the test, Theodor Seliwanoff.Full Answer >
A test tube holder's purpose is for holding test tubes in place, but they can also be useful for holding pipettes and stirring rods as well, and a test tube rack holds multiple test tubes in place. Some test tube racks can hold up to 40 test tubes. There are other racks designed for storing test tubes and holding even larger numbers of test tubes during a long period of time.Full Answer >