Flouride
fluride
A cast
yes
A rock having a cavity that is lined with crystals or mineral matter
A geode starts out as basically a cavity or pocket in otherwise solid rock. The cavity walls grow inward as mineral crystals grow from solutions that seep into it. In time, the cavity may become completely infilled with mineral crystal. The geodes that are found on the surface are survivors of weathering which eroded the rock in which they were once emplaced. This is because the geodes are composed of minerals such as quartz which are more resistant to erosion than the rocks which originally surrounded them.
This most likely is a cause of having something, generally a foreign object, pressed into your anal cavity. I would suggest taking a break and seeing if anything improves.
The Thoracic Cavity
it's stronger
No, it does not get stronger, the effect is completely opposite because some light gets absorbed, refracted and reflected by "mirrors". To make it stronger you need let light go through so called active body (cavity), then using so called stimulated (opposite to spontaneous) emission the beam can become stronger. It's how lasers work.
The thoracic cavity is superior to the abdominopelvic cavity.
Geodes. They can be found in some igneous rocks as well. They start as a hollow cavity created by a gas bubble or decaying organism. Mineral rich water seeps into the cavity and crystals form from the outside toward the inside.
The pelvic cavity is inferior to the abdominal cavity.
Chest cavity