The ruling planet of this Gem/Stone is SATURN (SATURDAY)

What you have to do:-

Donate - blue sapphire or another blue to purple gemstone, iron, steel, leather, farm land, a black cow, a cooking utensils, a buffalo, black mustard or  black sesamum seeds, to a poor man on Saturday evening.

Fasting - On Saturday during Saturn transits, and especially major or minor Saturn periods.

Mantra - "Aum pram prim praum sah shanaisharaya namah." To be chanted on Saturday, two hours and forty minutes before sunset, especially during major or minor Saturn periods.

This will help pleading Saturn (Shani) insuring victory in quarrels, over coming chronic pain, and bringing success to those engaged in the iron or steel trade.