The Platonic solid associated with fire is the tetrahedron. This is a four-side figure of triangles. (See link for an image.) Three sides are always visible one is hidden. This figure is especially important in my visualization of the soul and method of its operation. In the lore of the Western Tradition there are four aspects of fire volcanic, solar, astral and latent. These are associated with the four sides of the solid.
Researching these aspects of fire in Heremetic lore is pointless. I have been told again and again there is nothing to be found. In order to understand them, one must look to physics, fire science and meditation.
Today, in the shower, I had a personal epiphany about these forms of fire. So, right now I am working with this.
Volcanic is that fire which is so creative that it is destructive. It can best be shared as INRI, Igne Natura Renovatur Integra (All Nature WIll Be Renewed By Fire). This is the side that in operation of the soul must be left unseen. Revealing it makes one's fellow humans recoil into denial. No one wants to get renewed through fire!
Solar is that fire that sustains life. It is the perpetual expression of the life force. It's image is the solar sigil. This is forefront as microcosmically it is our personality.
Astral, this is the fire that creates something new. This is astral action that builds something there that it may manifest here. Its image is the lightening bolt. This can remain in sight because no one can see it.
Latent heat is the heat within all things at rest. It is the heat of the seed, potential. Yet it is also the the residual spent force of creation, like warm charcoal after a barbecue. The heat of the physical form. This is the only one I have ever heard anyone try to explain.
Some may read this and say this is not a big deal. For me, it is huge as I delve into the nature of the soul.