Mica,
actinolite/tremolite, calsite, pyrite, talc, feldspar, picotite.

In natural beryl the clusters of
phenakite crystals.
Liquid
inclusions: Healing
cracks, hollow tubes, two or three-phase inclusions.

Tube inclusions

Two phase inclusions have liquid with a
gas bubble in it. Three phase inclusions have also a crystal inclusion
in the liquid.
Structural
characteristics: These
are growth lines and color zoning.

The parallel growth lines creating a
"Venetian blind" effect are common in synthetic emeralds. But also you can see them in
natural emeralds like the one above.
Some characteristic inclusions which
tell us the origin of the stone:
Colombia:
Three
phase inclusions,growth zoning which is parallel to optic axis or follow
the crystal shape, mineral- crystal inclusions; pyrite, parisite,
calsite etc.
Rusia: Actinolite needles are
the most common.
Zimbabwe: Tremolite
needle inclusions
India: Oriented
two phase inclusions
Zambia: Mica,
oriented two phase inclusions
These oriented two phase inlusions are
special to Zambia and India.