How Gemology works: -

Gems generate constructive vibrations in the body. This helps counter the negative malefic powers released by the planets. When a specific gem is worn, it emits positive energy and provides a protective aura for the wearer.

Duration: - Every gem has a specific life span. After this period, one should change the gem as it loses its impact for that particular individual. Nevertheless, the same gem will be effective for another person.


Sun - Ruby----------------- 4 years
Moon - Pearl---------------2 years, 1 month, 27 days
Mars - Moonga-------------3 years, 3 days
Mercury - Panna(Emeralds)--3 years
Jupiter- Pukhraj (Topaz)---4 years, 4months, 18 days
Venus - Diamond---4 years, 4 months, 18 days
Saturn - Neelam (Sapphire)--5 years
Rahu - Gomed----------------5 years
Ketu - Cat's Eye---------------3 years


Note: - Gems should be cleaned with salt-water at least once a month.


In case you are unable to afford an expensive gem, here is a collection of secondary gems:



Main Stone---------------------- Secondary stones
Ruby :-Star Ruby, Sun Stone, Agate, Spinal Ruby, Spinel, Mysore.
Pearl :-Moonstone
Red Coral :-Garnet, Red Cornelian, Red Jasper.
Emerald :-Green Jade, Onyx, Green Aquamarine, Period, Turquoise.
Topaz :-Golden Topaz or Yellow Topaz.
Diamond :-Tourmaline, Rock Crystal, White Zircon, White Coral.
Blue Sapphire:-Amethyst, Black Topaz, Lapis Lazuli,
Gomed :-Brown Tourmaline, Brown Agate.
Cat's Eye :-Lapis Lazuli, Tiger's Eye, Agate, Turquoise.

who said that gemstones won't work after a certain period?
can u prove that?
are they some kinda timed logic or timebombs ? or what?

and if at all they stop working on a person, then howcome they work for a different person? do they sense/smell like dogs?

all they do is just send required light rays thru them to proper finger connected to proper nerve associated with a planet.

coral(which is not stone but kinda wood) may not be useful after 3-4 yrs bcoz, coral absorbs excess heat from body and burns itself, so it loses its weight over a period of time., so coral(which is anyway cheap) shud be replaced every 3 yrs.

rest are not wood but stones so no point of losing

its just a marketing strategy to sell them again and again.

more about how and why gemstones are formed can be seen in 'agni purana' written about 3000BC

and how they work can be seen in ' matsya purana'

Gems a a way of life so if you want the big picture of every one of the check this link.
.dirt-dog.com/kynna/gemology.htm