3.Groundmass
The largest units are in a dense mass that encompasses the smallest units.
Several types are defined depending on the proportion between the coarse and the fine constituents:
Open porphyric. The coarse grains are not very abundant and they float in a continuous
mass of fine material. This is the most frequent.
Double spaced porphyric. The grains
are separated at a distance equivalent to double their size.
Single spaced porphyric. The grains
are separated at a distance equivalent to their size.
Close porphyric. The grains have points
of contact with each other.