The softest and lightest gemstone on earth is amber. It is so light that it is able to float when in salt water. It is a stone that is a result of the sap and resin from prehistoric trees that have been fossilized. In order to be considered the gemstone that is amber, the fossilized sap needs to be at least 30 million years old. Most jewelry created with amber is made of Baltic amber, which is known to be the strongest type. It usually has a yellowish to orangish brown color but can be white, greenish, bluish, or even black.

The hardest gemstone is the diamond. The only thing that can scratch a diamond is another diamond. It measures a 10 on the Mohs hardness scale for gemstones, which means it is as hard as a gemstone can be. This is why diamonds are suitable for everyday wear in an engagement ring, because not much will damage the actual stone.