Molybdenum bronzes are classified in three major families:
* Red bronzes with limiting composition , that is, :
** Lithium molybdenum red bronze  Reau and others.
** Potassium molybdenum red bronze  or 
** Cesium molybdenum red bronze 
** Potassium molybdenum red bronze  a semi-conductor.
* Blue bronzes, with limiting composition , that is, . Their electronic properties generally do not depend on the metal A.
** Potassium molybdenum blue bronze  or 
** Rubidium molybdenum blue bronze 
** Thallium molybdenum blue bronze 
* Purple bronzes, generally with limiting formula .  Their electronic properties depend strongly on the metal A.
** Lithium molybdenum purple bronze 
** Sodium molybdenum purple bronze  
** Potassium molybdenum purple bronze 
** Rubidium molybdenum purple bronze 
** Thallium molybdenum purple bronze 
The hydrogen molybdenum bronzes have similar appearances but different compositions:
* Hydrogen molybdenum orthorhombic blue bronze , 0.23 &lt; x &lt; 0.4 
* Hydrogen molybdenum monoclinic blue bronze , 0.85 &lt; x &lt; 1.4 
* Hydrogen molybdenum red bronze , 1.55 &lt; x &lt; 1.72 
* Hydrogen molybdenum green bronze  or .  
Other molybdenum bronzes with anomalous electrical properties have been reported, which do not fit in these families.  These include 
* Tetragonal