The entrance of the cave was shaped into a monstrous beautiful sculptured dragon mouth.
Ji Yuan used his sword hilt to tap it gently before saying, "This is made of silver celestium stone stabs."
Celestiums are the densest stones in the Celestial Realm. There are two types of celestiums. Silver celestiums which are white in color and gold celestiums which are golden in color. It is often used in the palaces of the rich celestial clans and as treasury walls due to its ability to absorb shock.
Gold celestiums are three times denser than silver celestiums and are often called the 'indestructible stone' and are often used to seal off important passages. But at the same time, it is far more precious than silver celestiums and cost a 1000 times more than silver celestiums due to its scarcity.
At the same time, silver and gold celestiums can also be refined into fine metals known as Pure Celestiums to be used in precious swords and divine swords.
