India - 1701 Surat Rupee

Treasure of the Great Basses Reef, Lanka

SPECIFICATIONS Denomination One Rupee Alloy Silver Ag Type Struck Diameter 25.4 mm Thickness  mm Weight Legal 11.444 gms Weight 11.0 gms Shape Round Edge Plain DieAxis O° Mint Surat
Weight 10.6 gms Tone The coin above after dissolving out the thin layer of coral using HCl to reveal the XF surface that was beneath it.
	Brown #2985 ; Bombay KM#300

Obverse : Islamic text. with Year 1113 AH.
Reverse : On the center right of coin at 3 O'clock is 46 the year of the rule of Aurangzeb, and the mint mark four filled cicles (dots) around a thin cross which has a ring at center at the middle left at 9 O'clock

The couplet on the obverse of most of Aurangzeb's rupees is
sikka zad dar jahan cho badr monir shah aurangzeb 'alamgir which translates to
struck money through the world like the shining moon Shah Aurangzeb 'Alamgir.

The Islamic year 1113 AH started on 6th June 1701 and ended 28th May 1702. Regnal year 46 started on 1702 March 30th. Aurangzeb 1113 year coins are found with either year 45 and year 46. The coin above and the coin illustrated in Clarke's book clearly shows 46 although he mention year 45 in the text. Since Clarke does not mention the appearence of 45 on the face of coin it may have been computed (1113-1068) rather than read.

Various mint-marks were used on the Surat rupees of Aurangzeb according to the year of issue, each mint-mark usually being used for more than one year and are illustrated in 1920 Brown, Lucknow Museum catalogue Plates of Ornaments. For Surat 1113/46 The choices are four diamonds (M.90 #2984) or four dots around a cross ( M.193 #2985) illustrated on right which appears on the coins from this wreck. This was only used from 1113-1115 at Surat. For more details on AH years, Reginal Year and Mint Markc, see details of coins from a Hoard obtained in 2012.

To quote a report sent to Arthur Clarke by a chemist Dick Russell on 1963 June 3
A microscopic examination of the incrustation revealed sand particles cemented together with calcium carbonate. The sand was made up of particles of quartz, rose quartz, garnet, and a few which looked for all the world like rubies. ... The sand particles make up about 32% (by weight) of the incrustation. The lumps were stained with hydrated iron oxide and the exposed silver was invariably black with a coating of silver sulfide of varying thickness.

In general shipwreck coins are best left uncleaned. To quote Arthur Clarke and Mike Wilson from their 1964 book.
Most of the small conglomerations were left exactly as they were, with an eye on a possible future souvenir market. There are plenty of single Mogul rupees around and they are worth only about a dollar each. These coral-encrusted lumps, still smelling of the sea, are far more interesting and romantic than the individual coins they contain. We would actually be reducing their value if we took the trouble to break them up and clean them.

They describe the process they used to clean some of the loose coins.
Dick Russell devised two methods of cleaning the coins, one electrolytic and the other involving a two-bath process. The problem was to dissolve the incrustation without the resulting free sulphur attacking the silver. The first solution was made by dissolving 5 grams of sodium sulphite in 75 cc of water and adding 25 cc of concentrated hydrochloric acid. After the coral (calcium carbonate) incrustation had been dissolved, the coins were left with a thin but harmless layer of silver sulphide, which was removed with a brightener solution made by dissolving 50 grams of thiourea in 500 cc of water, adding 15 cc of concentrated hydrochloric acid and bringing the volume up to 1000 cc with water.

I could see detail in parts of the surface and I have another uncleaned coin in my collection. It was a real thrill for me to discover the clear XF detail when I washed out the thin layer of coral in 2000 October, using Hydrochloric Acid (31% HCl is sold as Muriatic acid in hardware stores for control of PH in swimming pools). The cleaned coin with about 0.4 gms of coral dissolved out is 7.4% under than legal weight.

This Coin was given in the 1960's to Rajah Wickremesinhe by Mike Wilson the co-discoverer of the Wreck. Rajah Wickremesinhe interpreted the blackened surface as evidence of a fire on the sinking ship. However there was no black beneath the thicker layer of coral on the observe when it was dissolved which does not appear to corroborate that inference.

Text from
* The Treasure of the Great Reef By Arthur C. Clarke with Mike Wilson 1964
* Catalogue of Coins in the Provincial Museum Lucknow by C. J. Brown Coins of the Mughal Emperors, Published for the United Provinces Government Oxford at the Clarendon Press 1920.

The uncleaned and subsequently cleaned coin was scanned at 300dpi and the images are displayed at 250dpi. The XF condition coin (after cleaning) was obtained in 2000 August from Rajah Wickremasinhe author and collector in Lanka
I thank Stan Goron, in UK and Richard Anderson in USA for contributing to this in reply to question I asked on the southasia-coins Egroup in 2001 August.