Gold  -  Au

 

 

This is a few tens of microns of 24 karats gold, plated on a copper surface. The total weight of these two objects is almost 5 grams. These two objects are used for high-power corrosion-resistant electrical connections, allowing many amperes of current to be switched in a corrosive environment.

Below, the same two objects are shown, with some reflected light and that picture nicely shows the beautiful color of gold metal. The gold surface is quite soft, the picture below shows that the upper object is somewhat scratched. For this reason, gold ornaments usually are made of an alloy of gold in order to make it harder. For electronics purposes, however, the gold is made very pure in order to have best conductivity.

 

Gold can also be made into very thin sheets and flakes. Below follows a sample of just over 500 mg of 99.99% gold metal. Despite the small amount of metal, quite a large volume can be occupied, due to the very thin sheets, used in this sample.

    

 

Another remarkable form of gold is crystalline gold. Gold can be made into beautiful crystals. The picture below shows crystals of a few mm diameter. The long structure has a length of almost 1 cm. This form of gold is compact, and the weight of these few crystals is more than the weight of the voluminous sample, shown above.

 

Below follow two close-ups of the crystalline gold: