Definite and characteristic heat of fusion.

Isotropic nature

A regular periodically repeated pattern of arrangement of constituent particles in the entire crystal.

A true solid

Graphite (C)

Quartz glass (SiO2)

Chrome alum

Silicon carbide (SiC)

Same in all directions

Different in different directions

Cannot be measured

Always zero

On heating they may become crystalline at certain temperature.

They may become crystalline on keeping for long time.

Amorphous solids can be moulded by heating.

They are anisotropic in nature.

a regular arrangement of constituent particles observed over a short distance in the crystal lattice.

a regular arrangement of constituent particles observed over a long distance in the crystal lattice.

same arrangement of constituent particles in different directions.

different arrangement of constituent particles in different directions.