precioso ADJECTIVE beautiful, lovely
Precioso has one meaning which is the same as precious in English. However, it’s much more often used in its other meaning of beautiful or lovely:
Llevaba puesto un precioso vestido de noche negro. She had on a beautiful black evening dress.
Tienen un niño precioso. They’ve got a lovely little boy.
In the meaning of precious it’s mainly used to refer to piedras preciosas, precious stones:
el contrabando de diamantes y piedras preciosas smuggling diamonds and precious stones