The underlying essence of existence is Oneness. That Oneness is called the Unified Field of Physics, Pure Consciousness, God, etc. As that Consciousness views itself, it sees itself as ‘other’ and ‘the pendulum swings’ in that direction. Duality, then multiplicity, is born.
It continues to see patterns in that self-interacting dynamic, causing the pendulum to swing this way and that, setting up numerous vibrations in the resulting structure.
That structure continues on at the basis of all existence. The vibrations permeate all existence in a symphony of Oneness… infinite harmony, intelligence, wholeness, etc. Some matter is tuned to one vibration while other matter is tuned to another. That determines the course of evolution of species, each along its own path.
As species evolve further, they move in the direction of a species that more and more fully embodies the totality of knowledge, vibrations, wholeness, that is inherent in the Oneness that birthed the Universe. Those vibrations direct the evolution of species and also the growth of crystals, i.e. gemstones.
By wearing a particular gemstone, the particular vibration it is tuned to permeates your being. So, if a particular vibration is needed by you, that vibration can be provided by wearing that gemstone. The science and technology of this knowledge is called jyotish. It is a subtle art. The science is valid.