Marakata or emeralds are known by their distinctive green color and can vary from light to dark green.  All emeralds contain inclusions formed during their growth.    Inclusions indicate  the stone is natural. The most common cut is the step or "emerald" cut.
Marakata or emerald harmonizes and strengthens the positive influences of Budha or mercury.  These influences include intelligence, education, speech, teaching, learning, communication, confidence, writing, drawing, trade, humour, wit, discrimination, diplomacy. intellect and commerce.  Budha or Mercury is the "prince" in Jyotish and is influenced by Surya and Chandra. Budha or Mercury in the human physiology is associated with the sub-thalamic nucleus which resides in the brain and receives input from various parts of the brain which directly influences its activity.  Similar to the placement of Budha or Mercury which revolves around Surya (Sun) and is directly influenced by that relationship, the sub-thalamic nucleus' activity is influenced by the input it receives and modulates its output accordingly.