In general, Calcite is a rock forming mineral with a chemical formula of CaCO3 (Calcium Carbonate). This is a very common mineral which is found throughout the world in sedimentary, metamorphic and igneous rocks. Geologists term calcite as an “ubiquitous mineral” – basically meaning that it is found everywhere. We call calcite a mineral as it is an element or chemical compound that is normally crystalline and formed as a result of geological processes over millions of years. Having said that, calcite is found in all types of rocks. However, in Malta it is only found in sedimentary rock; this being to the island’s geological formation.
Before delving further into the habit and properties of Maltese calcite, it is pertinent to write about the bedrock geology of the Maltese islands and how the islands came about. This geological history started to form about 30 to 25 million years ago (in geology terms this period is known as Miocene to the Pliocene periods). The rock strata at that time formed over millions of years through the accumulation of dead sea creatures and other marine crustaceans etc. Thus, calcite is often the primary constituent of the shells of these marine organisms. The islands of Malta are practically a mass of calcium carbonate which has formed underwater through the slow layering of sediments of these dead sea creatures. These bedrock strata would have settled under the water throughout the years. This is the reason why the bedrock in Malta is termed as “Sedimentary”.
The Maltese archipelago (situated between Italy and Tunisia) was created though the uplift of these sedimentary rocks. The uplift of the sedimentary rock was due to the pressure exerted by the plate tectonic movements of the African plate hitting the Eurasian plate during the late Miocene (23 to 5 million years ago) to the Pliocene period (5.333 million to 2.58 million years ago). When this phenomenon happened, the Mediterranean Sea was cut off from the rest of the oceans. When the rock strata were uplifted, it caused the drying up of the sea (actually, for the sea water to almost evaporate). This temporary drying up of the Mediterranean Sea is known as the “Messinian salinity crisis” near the end of the Miocene age. A land bridge thus merged connecting the Maltese islands with Europe through Sicily. Several animals migrated to Malta and still some of their remains can be found during quarrying.
At the end of the Ice Age, about 5 million years ago, the ice melted and so the sea level of the Atlantic Ocean rose. This caused the water to be spilled into the enclosed Mediterranean Sea. The Maltese islands were then again isolated from mainland Europe through this inundation of water. About 2 million years ago, the Mediterranean experienced another Ice Age. This time it was a wetter climate which ended about 10,000 years ago. This period is also known as “Aquitanian to Langhian” age. “Aquitanian Age” refers to dry, cooling period 20-30 million years ago and “Langhian Age” refers to a continuing warming up period, circa 16 million to 14 million years ago (this is approximately the middle of the Miocene period).
Now our readers can understand why the Maltese bedrock consists mainly of calcium carbonate material and why Malta does not hold any inorganic gemstones or other natural resources. This leads us to explain the composition of the Maltese bedrock.
The oldest exposed, bottom rock layer of Malta is the lower Coralline limestone Formation termed as “Zonqor” which is about 28-23 million years old. Next layer is the Globigerina Limestone known as “Franka stone”. This is a soft, limestone dating to about 23 to 14 million years old. The term “Globigerina” is derived from the fossil known as “Foraminfera”. This is the type of limestone which is used as building material throughout the Maltese islands. The next layer is the Blue Clay Formation known as “Tafal”. This layer forms an impermeable layer beneath the Greensand and the Upper Coralline limestone formations. It allows the capture of rainfall and the creation of aquifers. The next strata refer to the Greensand, known as “Gebla s-Safra” dating about 10 to 7 million years old.
This stone is very friable and unsuitable for building purposes. It’s position immediately above the Blue Clay allows for the infiltration of rainwater. The last layer is the Upper Coralline Limestone, known as “Tal-Qawwi”, formed about 7 million years ago. This last top layer is important as it is the youngest rock strata and it is in this layer that most of the calcite crystals are formed.
Rainwater picks up carbon dioxide from the air and as the water percolates through the top soil of the Upper Coralline strata, it turns into a weak carbonate acid. This acidic water slowly dissolves the limestone (carbonates) along the joints, the bedding planes and the fractures in the landmass. Sometimes, this water dissolves whole large volumes of calcium carbonates deep in the ground, and creates a cavern (a void). This is where Stalactites or Stalagmites are found. So, when calcium carbonate gets wet it dissolves to form a salt (in the chemical sense).
This acidic water is the result of precipitation which removes acids from the atmosphere and delivers it to the earth’s surface. During the hot seasons the Mediterranean Sea heats up, especially in summer, and it will no long absorb the carbon emissions that humans pump up in the atmosphere. Instead, the sea will start releasing it into the atmosphere to get it back when it rains. Together with this, is the acid rain which is caused by acids mixing with air.
The largest source is Sulphur dioxide; Carbon dioxide and various other oxides of nitrogen also make acid in the atmosphere. Lightning striking the ground during storms also create acids. When the calcium carbonates dissolve the calcite mix is born. This takes a multitude of years to take on a crystalline structure. Many times, we are left with a honey-coloured calcite, having a vitreous lustre and sometimes we find a mix of undissolved calcium carbonate together with this vitreous mineral (like a band of mixed colours) which may also contain several other impurities.
It is these impurities that give Maltese calcite crystals its honey-coloured transparency.
The Maltese calcite is a universally adored stone that can benefit anyone. Its energies are powerful as an environmental cleanser and energy amplifier. If a piece of this calcite is placed in a room it will cleanse the atmosphere of all negativity and heighten one’s physical energy. Without doubt this calcite will keep one grounded and concentrated to help one to reach his goals.
It is worth mentioning that in Malta, calcite is considered as a Gaia stone. The ancient Greeks referred to “Gaia” as the Mother Earth or Mother Goddess.
The Gaia theory goes back to 1970 when “chemist James Lovelock and his research partner Lynn Margulis, proposed that the earth is a living being, self-regulating the elements to sustain life on it. At that time this hypothesis was seen as heretical, but has since been accepted as fact, as theory, no longer hypothesis. Their work suggested that in the earth, chemicals all “talk” to one another to protect life on the planet; the salt in the ocean is never too salinated, the oxygen in the atmosphere never too noxious, and the temperature of the earth never grows too hostile for life to thrive.
All elements work in perfect harmony to ensure life on earth is sustained. The stability of life and its consistent ability to self-regulate and protect earth’s creatures connotes a universe much more intelligent than previously imagined. The Gaia theory taught that a sophisticatedly aware universe is regulating these many facets to protect and preserve life on the planet, much as mother protect her own children.”
Indeed, this is a wonderful natural crystal which is linked to the bedrock geology the Maltese islands.
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