Wisdom and Intelligence
These gemstones are associated with wisdom, logical choices, increasing intellect and fairness.

Aquamarine : Increase thought and intelligence.
Angelite : Help in Technical Studies.
Calcite : Thought to increase intellect, heal mental processes and increase wisdom.
Chrysocolla : Said to give wisdom to its wearer.
Diopside :Said to improve practicality, mathematical ability and intellect.
Fluorite : Thought to increase intellect and intelligence, esp. yellow variety.
Hessonite : Thought to rid one of profane, aggressive thoughts.
Iolite : Ability to discern truth.
Jade : Increase wisdom.
Labradorite : Improve the intellect, wisdom and use of power.
Lapis Lazuli : Used by ancient judges in Egypt to bring fairness and wisdom.
Marble : Improve intellect and wisdom, purify thoughts.
Onyx (Yellow) : Knowing when to keep silent.
Petrified Wood Agate : Increase wisdom and grounding.
Shell : Help make wise decisions.
Snow Quartz : Improve concentration.
Staurolite : Help discern truth.
Tourmaline (Yellow) : Increases wisdom and intelligence.
Tourmilated Quartz : Give the ability to see the truth