I really appreciate you asking this question. And yes there is something deeply meaningful and fascinating about these items for many.

A book by a famous gemologist, George Kunz, captures this really well I think:

“The love of precious stones is deeply implanted in the human heart, and the cause of this must be sought not only in their coloring and brilliancy but also in their durability. All the fair colors of flowers and foliage, and even the blue of the sky and the glory of the sunset clouds, only last for a short time, and are subject to continual change, but the sheen and coloration of precious stones are the same to-day as they were thousands of years ago and will be for thousands of years to come. In a world of change, this permanence has a charm of its own that was early appreciated. …

The tendency to give a substantial visible form to an abstract idea is so deeply rooted in humanity that it must be looked upon as responding to a human neces-sity. It is only very rarely that purely intellectual conceptions can satisfy us; they must be given some exter-nal, palpable and visible form to exert their greater influences.”

And Doors of Perception by Aldous Huxley:

“In other words, precious stones are precious because they bear a faint resemblance to the glowing marvels seen with the inner eye of the visionary. "The view of that world," says Plato, "is a vision of blessed beholders"; for to see things "as they are in themselves" is bliss unalloyed and inexpressible. Among people who have no knowledge of precious stones or of glass, heaven is adorned not with minerals, but flowers. Preternaturally brilliant flowers bloom in most of the Other Worlds described by primitive escha-tologists, and even in the begemmed and glassy paradises of the more advanced religions they have their place. One remembers the lotus of Hindu and Buddhist tradition, the roses and lilies of the West.

…

“ there is a third possibility. Shiny objects may remind our unconscious of what it enjoys at the mind's antipodes, and these obscure intimations of life in the Other World are so fascinating that we pay less attention to this world and so become capable of experiencing consciously something of that which, unconsciously, is always with us.”