Gold is often used to protect other metals from corrosion. It so effectively resists corrosion that gold is plated over metals like copper when contact resistance is critical, such as in stereo or HDMI connectors. You have probably seen photos of gold coins that were discovered in shipwrecks. The coins were in salt water for hundreds of years and look pristine. Gold also melts at a relatively high 1064oC.
So, it would seem that gold is invincible. However, mercury at room temperature will dissolve gold. See this interesting video that shows this effect. This property of low- temperature melting metals dissolving high-temperature melting metals at lower temperatures is one of the principles behind Indium Corporation’ s DurafuseTM. See Figure 1.
Figure 1. DurafuseTM is a Low-Melting/High-Remelting Alloy System
Gallium metal exhibits this property with aluminum. See this comical video of gallium dissolving a soda can. Gallium is liquid at slightly above room temperature (about 30oC) and has many interesting properties. See Figure 2.
Figure 2. Gallium is an interesting metal. It is non-toxic and melts at a little above room temperature. See this link to watch the video.
Indium Corporation is working with Professor Michael Dickey of North Carolina State University to investigate these properties. It is expected that numerous useful applications will come from this work.