The geode formation is one of the most attractive crystalline formations you can find in the mineral world. They are cavities (often roundish in shape) inside rock which are lined with crystals, often in different colored layers. Such cavities are also called vugs. Not all geodes have an empty space within them; some geodes are solid cavities filled up with another type of mineral (like thundereggs).
Geodes are common in sedimentary rocks, but can also be found in igneous rocks. Most geodes are comprised of quartz or chalcedony lining the interior, while the exterior is of another type of rock, often limestone.
Many geodes form when the rock around gas bubbles harden, leaving a small cave inside, which then becomes lined with crystal deposits after mineral-rich hydrothermal liquids inside them evaporate. Geodes can also occur inside pyrite when silica rich cavities inside them evaporate, leaving behind small crystalline caverns.
Geodes range in size from tiny to huge sized ones, basically mini caves. The most common geodes are amethyst and clear quartz geodes. Citrine geodes are far less common; many so-called citrine geodes are actually heat treated amethyst geodes. Also, many geodes with vivid color banding have been artificially dyed by soaking them color solutions. Thundereggs comprising agate and other types of chalcedony are also common in the crystal market.
Amethyst geodes
This is an amethyst geode of mine, for example, weighing about 5 kilos. It has been sliced into two to reveal the numerous crystals inside. There is also a large calcite crystal amongst the amethyst crystals. The exterior rock is composed of agate bands.
Above – The small amethyst crystals lining the geode interior. Never expose amethyst geodes to sunlight; they will fade.
Above – The agate banding underneath the amethyst cluster.
Above – A large calcite crystal inside the geode.
Above – The encrusting rock is often composed of limestone, a porous and soft rock.
Metaphysical aspects of geodes
From the metaphysical point of view, geodes are wonderful for family harmony and the home. They are good for stimulating creativity and harmony. Large geodes placed in home corners help to stimulate chi flow in that area. Placing a crystal inside a geode helps to cleanse and recharge it at the same time; think of geodes as power generators comprising the sum total of ALL the little crystals it contains! On another level, geodes actually represent the divine feminine aspect. The cavity within the geode may be taken to symbolize the womb.
These qualities are in addition to the individual properties of the crystals on the lining surface, as well as the mineral comprising the banding beneath. This means an amethyst geode, for example, will exhibit the amplified metaphysical properties of its amethyst crystals as well as the properties of the agate underlying them. Placing a small amethyst geode near your bedside table may well be the sleep panacea you have been searching for.