Diamond model
The crystalline structure of the diamond is derived from the centred face cubic structure: in addition to the atoms at the corners of the cube and at the centre of each face of the CFC structure, four of the eight tetrahedral sites are occupied by carbon atoms giving a total of eight atoms per mesh instead of four for a CFC structure.
Dimensions: 17 x 17 cm
Réf : RCDIAM
 
Graphite model
The model makes it possible to visualise the lamellar assembly of the graphite. The crystal lattice consists of parallel planes of hexagonal structure in which the carbon atoms are strongly bonded. These planes are equidistant (3.35 Å between two layers) and weakly linked together by Van der Waals bonding forces. The layers can thus slide on one another, explaining the layering and the low hardness of the graphite.
Dimensions: 28 x 32 cm
Réf : RCGRAF