Mercury: Emerald gives mental alertness, memory, communication skills, discriminative intellect and mental control. When Mercury is weak or afflicted, a mental dullness, immaturity or poor memory retention may be evident. The logical part of the mind is not functioning in a normal way, which may cause daydreaming, anxiety, fantasies or an irrational outlook on the world. As mentioned, the Moon or Rahu can cause somewhat similar complaints, but Mercury is specifically the planet of intellect and communication. Emerald is generally pretty safe, unless the person is already overly mental. Aries and Scorpio Ascendants may find that it boosts their impulsiveness or egoism. It is especially favorable for Gemini, Virgo, Taurus and Libra Ascendants.
Emeralds are also gems of legendary expense, but fortunately can be grown in the laboratory with great results. Lab-grown emeralds are easy to identify because they are usually flawless and of deep green color. Natural emeralds under the microscope show an extensive “garden” of inclusions. These inclusions can affect the astrological potency of the gem. In the case of emeralds, the depth of green color and uninterrupted amplification of power given off by an unfractured lab-grown crystal is vastly superior to a highly included natural emerald of the same color that would have a carat value (and cost) of at least 40 times the lab-grown crystal. I offer large faceted, deep green lab-grown emeralds for $55 to $75 a carat.
It is worth noting that most good quality emeralds have their fractures vacuum acid-cleaned, after which they are heated and pressure-impregnated with a dyed synthetic resin with the same refractive index as the beryl crystal. This process is designed to enhance their appearance and thereby justify an inflated price. In reality it only disguises the gems’ heavily flawed condition (but such are the forces that drive the gem market!). Many people who have had their jewelry cleaned were unaware that the sonic cleaners had eradicated the coloring agents in their emeralds and have then sometimes unfairly accused their jewelers of switching stones!