Calcination began as the earth was formed from the nebulous gasses of the Milky Way. The molten core of the Earth was so hot that volcanoes erupted constantly and the Earth had no atmosphere. Thus, no life was possible. Eventually the core cooled a bit and Dissolution was possible. Oceans formed and land masses solidified created the pan-continent. Algae began to grow in the oceans and this gave rise to oxygen and an atmosphere, via photosynthesis. This was about 1 Billion years ago. The newly formed atmosphere gave protection to the Earth against the harmful Solar radiation. This relates to personal alchemy in that before the process is undertaken, the force of Consciousness (Solar Radiation) is harmful due to its unintentional misuse. The pre-historic life that exists during this period begins to Separate.
The greater land mass begins to drift apart creating continents, and life diversifies into trees, plants, and eventually Dinosaurs. These new identities relate to the individual assessing the various aspects of its own life-force. Conjunction comes about as life continues to diversify. The chaos has settled and the Earth now hosts a multitude of organized life. In the Alchemical process of our mother Earth, Fermentation would correspond with the theory of a great meteorite hitting the Earth and wiping out nearly all animal life. The Distillation of life happens very close to this period. After the dust settles and the light of the Sun again nourishes the Earth, primates arise and begin to organize into groups and our human-life ancestors begin to gain control of their environment, creating tribal structures which lead to increased intelligence and primitive utilitarianism. I feel that the process of Distillation is still occurring on our planet, and indeed our state of affairs is evidence that the process of Alchemy and evolution is an organic one.
Once the people of the Earth unite as one race and embrace our heritage as children of the Earth, we might attain Coagulation. Yet I feel that we will have to undergo a few more cycles of Calcination to Distillation before a pure Greater Stone of Earth will come to be. I think this is pretty far down the line. Given the state of US political powers, and the state of world affairs- the fundamental Islamists wanting to kill all the Jews and then the Christians (then finally themselves, we can only imagine) and the nuclear arms issues with Korea and Iran- we see a nice set up for a recurring period of Calcination in our world-society. But these conflicts could easily be carried out over the next few hundred years, eventually coming to a climax. The population would then have to sift through the rubble and figure out what is necessary and valuable to the earth-society, provided there are any humans left.
Without getting overly political, I will say that whatever the manifestation of consciousness on our planet, it will cycle through the stages of Alchemy until a unified Coagulated population is established. This could take many hundreds or thousands of years. It could possibly never happen, if our planet destructs due to depletion of resources or the extinguishing of our Sun. Even in the event of a world-wide nuclear suicide, life will continue to evolve out of the rubble- maybe just the cockroaches.