Chinese coins refer to the lucky coins that are considered a source of wealth. 
The circular coins have its two sides representing the yin and the yang and a square opening at the center. Four characters are inscribed on the four sides of the yang, whereas the yin may have two characters or be kept blank. 
The round shape of the coins denotes heaven while the square opening symbolises earth. Usually, bunches of three, six or nine Feng Shui coins are tied together with a red or yellow ribbon. 
Red is an auspicious colour in Feng Shui and is associated with life force, energy, vitality and protection.
 
The coins, representing the metal element, bring positive energies and prosperity for the owner.