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Yours truly above the Cavansite deposit in vesicular basalt in the bottom of Chavan Quarry, Wagholi, 20 km east of Pune (Poonah), India. Cavansite only occurs in the small pit in the bottom of the quarry; all other basalt is massive and hence excellent for road material. The vesicular basalt with Cavansite is useless for road material, but we will probably find another use for it!

Cavansite was originally described as a blue associate of zeolites from Owyhee Dam, Owyhee Co., Oregon, USA by Staples et al. (1973) and the structure was determined by Evans (1973). It was another of these ho-hum mineral discoveries, of interest to an eclectic crowd only; interesting crystallography and chemistry, but just another smirch on rock. I got my first piece in 1982, and it was a distinctly low-grade Heulandite with pale greenish inclusions, allowing me to check off Cavansite in the book.

An unusual blue mineral, later identified as Cavansite, showed up in a handful of specimens of zeolites from 'Poona' in late 1973 (Birch, 1977; Kothavala, 1991). It caused quite a stir as the specimens were not only markedly better than any of the original Cavansite, but actually attractive! Regrettably nobody knew where the specimens were collected. Then, like now, 'Poona' was the claimed locality of many specimens, with little consideration of where they actually came from, because that is where most wholesalers live.

The Deccan Traps, famous as a prolific source of zeolite specimens, currently covers an area of approximately 470,000 square kilometer in western India, but probably used to cover at least 1.2 million square kilometers after deposition in the late Cretaceous (Wadia, 1966). Far from all of it produces specimens worth having, but it is a huge area to cover, looking for blue specks and needles! Most of the Deccan Traps are composed of an Augite basalt that is chemically and mineralogically extremely uniform. It forms layers up to 3000 meter thickness in the west around Bombay, but dwindles to 30-150 meter near the rim (Wadia, 1966). The basalt is generally poor in vesicles. The reason why we see the abundance of zeolites and other minerals from the Deccan Traps is its immense area and extensive use for road material. Most of the zeolites come from within short distance of either Pune or Nasik, and yet the production from each individual quarry is sporadic at best. Do not expect to see an abundance of druses if you visit the area; there are often weeks or months between finds of any consequence in a given quarry. To add insult to injury, if there ever was a quarry with abundant druses, we would probably never hear of it! The quarries' chief product is road material and druses appreciably depreciate the value of the rock. Consequently, a quarry often encountering druses would be abandoned.

In 1988 Nagappa Banpatte found Cavansite in the Dhoot Quarry at Wagholi approximately 20 km northeast of Pune. He found a few pieces of radiant blue needles perched on snow white Stilbite crystals. Being an old hand in the mine, he recognised it as something new and interesting and brought the specimens home. Later he gave the pieces to 'two drunks' working as 'runners' in the area. 'Runners' pay frequent visits to the quarries producing specimens, buy material from the workers and sell to the mineral dealers. If they come across a large or expensive lot, they bring the dealer to the quarry and get a reward or commission in stead. The 'two drunks' brought the specimens to a dealer, who was not at home and 'eager to get a drink' went to another. That dealer later sold the specimens to 'a German', whom I presume is Hans-JŸrgen Wilke (see Wilke, 1989). He managed to track down the quarry and with an Indian partner, Arvind Bhale, paid to get a lease on the part carrying Cavansite. Wilke (1989) describes the operation of the quarry and extraction of specimens, which does not sound particularly simple. The material hit the mineral market like a bomb shell at the Tucson Show in early 1989. The colour was a vibrant blue and rather than grains intergrown in zeolites, the Indian specimens had needle crystals up to 10 mm long, forming spherules and tufts on white Stilbite. This was a quantum leap in quality for an obscure species and new finds have repeatedly earned rave reviews ever since.

Kothavala (1991) recounts the usual story of competition between illicit specimen mining - the quest for the easy buck - and the quarry's normal operation. We've heard it many times before (and since), where workers pursue valuable specimens either during work hours or in the night, thus ignoring work at day. I will be the last to criticize anybody for pursuing his luck or even for trying to earn easy money, yet I am surprised there has to be a deep economic and social conflict in having a valuable raw material readily available.
In 1990 the Indian mineral dealer M.F. Makki explored other quarries in the area and managed to locate a new deposit in May 1990, that proved equally good to the Dhoot Quarry, that was by then inaccessible except to illicit activities. Cavansite was subsequently found in the nearby Chavan Quarry and another quarry, bringing the total number of deposits to four quarries in Wagholi. The quarries are huge workings for road material with dozens of rock crushers, but a small corner in each carries another type of brecciated andesitic basalt. Zeolites, chiefly single crystals of Stilbite, or minute crystals of Calcite coat the interior of the vesicles. Cavansite is not abundant, but some vesicles carry aggregates of Cavansite blades in balls between 5 and 15 mm across, whose incredible colour is a stark contrast to the brown basalt and white zeolites and Calcite.

The Cavansite quarries - that is a small part of each quarry carrying Cavansite - are only worked sporadically, and there is no continuous production. Currently (early June 2000) two are closed, one is flooded due to monsoon, and one (Chavan) is in operation. Note that 'in operation' does not mean somebody is hauling out loads of Cavansite on a daily basis; there can be months between major finds. In early June 2000 a major find in the Chavan Quarry produced a handful of absolutely exquisite specimens and about three hundred specimens ranging in quality from very good to landfill.