CORALS (MARJAN)

What is Coral (Marjan)

Coral used as gem which is valued a lot due to its beautiful appearance and color. Coral is also commonly known by the name “Marjan”.  It’s a common thought that Coral is a stone, which is extracted from some mountain, well that’s wrong.

Coral is produced under water through a biological process. An invertebrate known as Polyp or Coral Polyp, this organism is related to Jellyfishes or Sea anemones. It is a small soft bodied creature with a hard base shell of limestone skeleton.

Coral Polyp attaches itself to a rock deep on the sea bed, Coral Polyps form a colony on the rock and with passage of time colonies connect to each other and form a branched like structure called Coral Reef.

It’s a very long process after which branches are formed which are used as gem, history states that there are colonies present which are million years old. Average age of Polyps are 2 years to even centuries.

Coral Polyps are basically translucent, so how these reef give such beautiful colors is the question. Well, Polyps host with Zooxanthellae which are algae with such beautiful hues.

Polyp’s colonies are found in many places around the world but in tropical waters, generally close to the surface, where sunlight reaches the algae. Corals get the food in form of byproducts of algae during photosynthesis or they have venomous tentacles which they stick out to catch Zooplankton or tiny fishes, which they do at night.

Corals are soft, so they are said to be treated with care as they take there place on 3 – 3.5 Mohs Scale of Hardness out of 10.

Coral are dying due to human factors like Pollution, Global warming which are a threat to the existence of Coral reefs.

 

Origin:

Corals are found mostly in tropical even sub-tropical salt water areas. Torre del Greco (Italy) is the oldest known source of the best quality Corals. It was the trading center for roughly over 200 years. It satisfied almost 75% of the world demand.

Mediterranean Sea is rich with high quality vibrant colored Coral reef especially western side of the sea, in Sardinia. Not only this, deposits are also found in Red Sea, Malaysian Archipelago, Bay of Biscay, Australian Coasts, Canary Islands (Spanish Archipelago), Hawaiian Archipelago, Taiwan, Pakistan, Afghanistan, Sri Lanka and many more.

 

Colors of Coral (Marjan)

Corals are found in many colors ranging from White, Pink, Orange, Red, Golden, Gray, Black and Bluish shaded ones which is said to be rare and more inclined towards gray shade.

Corals are naturally Matt colored, but to increase the value they are polished to give a beautiful bright glossy look.

Two basic divisions of Corals are.

Calcareous Corals: They are composed of Calcite and are of White, Pink, Orange and Red colored.

Conchiolin Corals: They are composed of Conchiolin, it is also present in pearls. They have colors Gray, Black, Golden sometimes even Brown and Blue ones are also related to Conchiolin Corals.

Conchiolin Corals are comparatively tougher then Calcareous Corals.

 

White Coral (Marjan)

White Coral has a beautiful color and is used in jewelry in different rings, bracelets and other ornaments. 

Though it’s a Coral but this color is not of that much value in the market then the ones with shades of red.

Yet it has its own beauty and is preferred by many.

 

Red Coral (Marjan)

The most valued color among the Corals is Red or Pinkish red to orange red. It belongs to Coralliidae Family.

The red of the Coral has lots of stories to it, one is that, Zeus the Greek god when killed Medusa her blood fell in sea and that blood became Red Coral.

Red Coral is also called Corallium Rubrum and Precious Coral.

 

Black Coral (Marjan)

Black Corals also known as Antipatharians are of black to dark brownish even gray colored. They are found in many locations and depth but they are mostly related to Hawaii and Cameroon.

Black Corals gets its name due to its black skeleton, which composes of Chitin & Protein. It is not much used in jewelry because it is considered rare just like blue and golden.

Black Coral is said to be the official state gem of Hawaii and its trade is heavily regulated.

 

Golden Coral (Marjan)

The famous Golden Corals of Hawaiian region it is said to be very rare and are very ancient colonies of Coral Reef. They are found deep in seamounts near Hawaii.

Researchers state its colonies to be of 5000 year old, among which only one is said to of 2740 years old. It was long used commercially in jewelries until it became rare.

It’s also value for its Iridescent (Cat Eye Effect) properties and the products made out of such Corals are highly valued.

 

Blue Coral (Marjan)

Blue Corals are very rare and are said to have massive skeleton. It has very beautiful blue to grayish blue shade to it.

They get this color because of iron salt and is composed of Calcium Carbonate and are very rare.

They are said to be in threat due to Aquarium Harvesting, Habitat Destruction, Climate Changes and Acidification of oceans.

Blue Corals are found in Indian Ocean, Pacific Ocean, Great Barrier Reef Australia and it is said that the largest colony is located at Ishigaki Island in Yaeyama Islands, Japan.