Stone, Rock
The stone or rock is especially suitable as a symbol for the Self because it represents pure nature; it just is. "It remains itself, exists for itself ... a state of absolute being," says Eliade (Patterns in Comparative Religion, p. 216).
Our inner core
Although the stone is so completely different from humans, it symbolizes our innermost core, the part of us that is free from emotions, thoughts, and attitudes. It is a unit that just exists and never changes. It is the simplest of objects, but at the same time, something deep, eternal, and mysterious. This allegory appears among Gnostics and alchemists, for example. In such mystical contexts, there is a connection between the small stone and the large mountain, which is, so to speak, the same thing.
Earth’s stars
Stars in the sky express a similar symbolic value to stones on the ground; a valuable stone in a dream can be seen as a star on earth.
Alchemy
The above are essential reasons why the alchemists' goal was called the "stone," the philosopher's stone; it contains everything (compare Egg) and is the union of opposites. For the alchemists, there are many similarities drawn between Christ, the rock, the stone, and the cornerstone; lapis is a "sacred rock," often quadripartite. They also describe how water or oil flows from the rock, and in 1 Corinthians (10:4) it says, "They drank from a spiritual rock that followed them, and that rock was Christ."
The alchemists also speak of a "dragon stone" found in the round fish, in dragons, or in the heads of water serpents. It is said to be white in color and a powerful antidote.
One imagines the spirit in the stone, speaking of the "serpent in the stone," "God in the stone," and so on; the stone is unshakable and spiritual. The oldest reference to "mercurial spirit" in alchemy, according to Jung, might be older than Christianity and goes: "Go to the Nile rivers, there you will find a stone that has a spirit." (Alchemical Studies, par. 265)
The sacred
The stone is one of humanity's oldest symbols for the sacred; it is something gods like Mithras have sprung from, and according to some beliefs, the home of children's souls. Magical stones have been used everywhere, and sacred places have been marked by the eternal stone throughout the world and throughout time. Both in Jerusalem and in Mecca, the sacred, eternal, and the center of the world have been symbolized by a stone.
The stone is eternal and unchanging, in complete rest – it is outside of time. This state reappears in Buddhism and yoga, where there is a striving to achieve stillness, immobility, in terms of actions, thoughts, and, of course, spiritually. In this way, they escape historical time and enter into sacred time or eternity, or like the stone, into an eternal now.
Both saints and heroes have transformed into or made themselves into stone as an expression of the eternal good or as protection against evil. "Christ is our rock, Jesus is our cornerstone" (1 Peter 2:4) etc. Similar things were said by the Nasarenes about Adam.
Religion
In Deuteronomy 32:4 and Psalms 19:15, God is likened to a rock. In general, there is a connection between the father-god and the rock in religious contexts.
The rock represents the unshakable and permanent, just as one imagines the Father or religion.
In Chinese philosophy, the rock represents yang, while the waterfall represents yin.
Stones in everyday life and ritual
Humans have a tendency to pick up and carry fine or unusual stones, without any rational reason for it; an impulse that seems as old as humanity itself. Perhaps we project our own life force and the mystery of life onto stones? It feels as though they are valuable, even though they can hardly be sold and exist in endless amounts. But the seemingly valuable stone that proves to be the highest recurs not only in alchemy but also in the already cited 1 Peter: "Come to him, the living stone, who was indeed rejected by men but chosen and precious in the sight of God. And let yourselves, like living stones, be built into a spiritual house..." (2:4-5).
Although the stone in alchemy is the goal in itself, stones in rituals and religions are rather instruments, tools, to achieve something.
The Eternal
The stone is eternal, and perhaps that is why we use gravestones, so that the memory of the person will last forever, or as an expression of eternity on the other side. Humans have always erected stones as memorials, and according to many religious traditions, people gather around a stone. Similarly, statues have been erected in ancient times for what they symbolize to last forever.