Indian Dendritic Agates ( Indian Moss Agate)

'''Dendritic Agates'''

Agates are one of the most diverse and unusual stones amongst all the rocks found on earth...Though they have been immensely valued across the history of mankind in most important cultures, they are rarely understood.
Amongst agates, Dendritic agates have their own unique place but like other agates they are little known and often confused with man made materials...because they are too good to be true?


== Indian Dendritic Agates ==

History

India has a long history of Agate trade with historical references suggesting agate trade from the port of Cambay dating back to over 2000 years. It is widely believed, though not established and widely debated too that a lot of the ancient agateware used by the early Romans and its origins in India.
There is also enough credible evidence regarding thriving agate mining, cutting and polishing industries in the Rajpipla and Limdora areas in North and western India with a thriving trade reaching most of the old world.

Yet, Dendritic agates from India have a aura of mystery around them with the mines and exact lapidary processes still reasonably well kept secrets. Dendritic agates from India were first discovered around 400 years back but gained importance in the reign of Bundela King Chhatrsal who was a patron of arts and encouraged budding lapidary craftsmen engaged in agate cutting. There are numerous legends regarding how these wondrous dendritic agates were accidentally discovered but not many of the accounts are verifiable. But it is universally accepted that the mining and cutting really took off after the Chhatrsal fell in love with these “paintings by God”.
It is not known how exactly these stones reached Europe first but as it was with trade routes; these stones took a circuitous route through the Middle Eastern port of Mucca and were soon being called “Mocha Stone”, fabulous examples of Indian dendritic agates can be seen in antique Victorian estate jewels. Even Faberge, the famed Russian jeweler was not immune from their influence and numerous of designs and pieces using Indian dendritic agates attributable to Faberge can be found across Europe. Faberge even referred to these stones in his personal journal thought I am flummoxed at his mistakenly (I presume it was a mistake) calling them “Orskaia Jaspers”, a reference which can not be found anywhere else.

Geology

Found at the edges of the famed Deccan Traps of India, the largest volcanic flood basalt region in the world, Indian Dendritic agates were formed by an intriguing set of geological co-incidences coinciding with the mysterious K-T mass extinctions around 60-80 million years back at the end of the Cretaceous period and around the advent of the Tertiary period in geological history. This period occurrences in the Deccan traps have often also been linked to the extinction of the dinosaurs. Most of the soil (95%) in this region consists of the tholeiitic basalts and rest being other minor but related occurrences. The area is also linked to the Shiva crater, a vast meteorite impact crater of around 65 million years back in close to the west coast of India.

Chemically these agates are quartz nodules with atypical banding and occasional druzy hearts with a hardness of around 7 on the Moh’s scale. Some nodules have yellow skins though that is again not a typical feature. The impressions though are still a scientific debate though most opinions point to the purely inorganic depositions of iron, magnesium and tin ions while a smaller school of thought believes that these were organic material replaced by ion exchange process over millions of years by inorganic metal salts and agatized.

There are two primary occurrences of Indian Dendritic agates spread over an area of about 50 kms radius in West Central India. The primary occurrence is of secondary river bed deposits in one of the tributaries of the Mighty Narmada river that has been weathered down by water and is a regenerating source after the annual post monsoon floods and is often associated with the transparent and more finely imprinted stones while the second inland source is associated with the translucent stones which are again sub characterized according to the regional peculiarities and are mined from the grey green volcanic ash beds at the depths of 40-85 feet.

While the river bed agates have mostly black, brown and rarely green dendrites on a glassy surface, the inland agates display a variety of grounds and imprints ranging from while, yellow, grey grounds and imprints in almost every color ranging from the common black and browns to red and the extremely rare yellows and purples with every 500 yards giving their very own typical signature to the stones.
The variety of colors is attributed to the presence of other minerals that get mixed in the siliceous fluids with each mineral being responsible for a different color
Iron-oxide = orange, rust, red or yellow.

Manganese-oxide = blues, blacks or purples.

carnotite (a compound of uranium) = brilliant oranges and bright yellows.

chromium = soft green

cinnabar = true rose or baby-pink

chlorite = deep green

Mining / Gathering

The river bed mining takes place in two major phases every year, the first being January –February when the river bed is dry and cucumbers and other deep rooting vines are planted in the river bed, these fast growing vines mature in a month and the deep and fast growing roots churn the soft alluvium resulting in many nodules coming to the top and are easily collected for sorting by experienced sorters.

The second and most important phase of gathering takes place post the annual monsoon floods around the end of June till around September –October when the flood waters weather and break the boulders and the nodules come to the surface after the flood waters recede.

Though easy it may sound, its not a child’s play as only one in 100 nodules bear a dendrite which often occurs deep in the heart of the stone perpendicular to the bandings and sometimes on the gravely quartz matrix. The dark, translucent yellow and black skins of the nodules make it very difficult to figure out what is inside the stone.

The collected nodules are then very slowly and painstakingly sorted for any evidence of a dendrite, small chips and cracks are looked for and into, small cracks made on the surface and the possible direction of the cleavage is determined to break the stone accordingly. This method though still is not error free and many times a good dendrite and my heart gets broken with a careless hammer stroke. The cracked nodules are then dipped in water and held against the sunlight took for the deceptive signs of dendrites and it takes years and years of experience to be able to figure out the secrets in the heart of the stone.

Cutting / Polishing

The cutting process despite the advent of the gem saws has still remained the same for the last 400 years. The finally sorted stones are then sent to the master cutters who use a length of bow string coated with silicon carbide mounted on a wooden stand to slowly grind layer by layer until the dendrite bearing layer is reached. It is a painstaking process because the layers are very fine and the dendritic impressions even finer and not more than a few microns thick. One wrong stroke and a beautiful gem can be ruined. A good sized nodule often takes days to cut and often it comes out empty with just a small spot of speck of dendrite. Truly majestic dendrites are extremely rare and are often celebrated like the birth of a child. A single nodule can sometimes also throw up more than one dendrite and not always is a dendrite flat. Some rare stones have three dimensional floating dendrites that though are the most difficult to cut, yet result in the finest of specimens including the famed “Maharaja”

The sliced agates are then cut in shapes according to the dendrite impressions and made into flat cabochons which can sometimes be wafer thin. The polish used is most often Cerium oxide though other polishes are also sometimes used and the stone is then slowly hand ground on a polishing wheel using a felt backing until the polish is set. In all the cutting and polishing is a 8 step process done entirely by hand though modern lapidary equipment is being used more often now, yet the best stones are still cut the old way to bring out the best results.

The incredible journey of a beautiful dendrite has just begun and for us the challenge of presenting it in way that does justice to its beauty is a personal one at the House of Indus. Enhancing a stone is a cardinal sin with us, traditions are strictly followed and every stone is not just a masterpiece of nature’s artistry but also a hallmark of excellence in workmanship.

The finished dendritic agates are again graded and the best ones go into the private collection of the family, for which it is much more than a business. Apart from loose cabochons, a lot of other interesting products and accessories are manufactured by our artisans under the brand name “Paarijat” which according to Indian mythology derives its name from the golden flowers of the wish tree that grows in heaven and under which all your wishes come true.

From a religious point of view the dendritic / moss agates have great significance in the Middle Eastern culture where these are known as “shazar” and are supposed to protect the wearer from misfortune and bring fertility and prosperity in enterprise.

They are known by various names in different cultures like Mocha stone, picture agate, moss agate etc and various magical properties are attributed to them, but for me, the beauty is magical enough. I hardly care if the occurrence is organic, or inorganic, of if the stones will bring me luck…they bring joy to my heart is enough!

They are indeed poetry in stone!

Copyright 2009 Tarun Adlakha http://www.indus-valley.in/ , tarun@adlakha.in

Notes

Mocha Stone: The origin of the term Mocha stone dates back to the times preceding the British Raj when middle eastern ports were a major transshipment point for Indian goods into Europe and some of these stones reached England through the Yemeni port of Mucca, giving the name.