Adze tridacna gigas (giant clam shell)
Two fine examples, in good condition, of the tool that populated the Pacific.
Length: 14cm (5.5 inches).
Pair US $500
The Tridacna shell for adze production, particularly the thick part near the hinge, was in former times highly and widely esteemed for this purpose, as is recorded by Keate from the Pelews, by Finsch from the Carolines, Marshalls, and Gilberts, by Guppy from the Solomons, by Dixon from Malden Island, by Wilkes from the Paumotus, by Moseley from the Admiralties; and from Nanomea in the Ellice itself Finsch obtained a specimen of a Tridacna axe.
It would hardly have been anticipated that natives, like the Solomon and Pelew Islanders, in the possession of hard volcanic rock would have thus used this material, but Finsch repeatedly remarks that the greater toughness of the shell gives it an advantage over the more brittle stone.
In the Carolines the same author found the Tridacna blades to assume various shapes, of which he figures a broad deltoid and a narrow chisel form. Some of these attain an immense size, reaching twenty inches in length and ten pounds in weight; such, he says, were common property. In every case the shell was Tridacna, though it is probable that in Funafuti, as elsewhere in the Pacific, other mollusca such as Mitra episcopalis, or Terebra maculata, would sometimes furnish adze-heads.
Describing relics of the race who formerly inhabited Malden Island, Mr. W. A. Dixon writes:—"In the grave was a hatchet head with polished edge made from the shell of a tridacna… In many places there were numerous axe heads chipped roughly out of tridacna shells. These are tolerably easily made, the shell being first broken transversely, when a blow on the fractured surface breaks out from the interior of the shell an adze-shaped piece which seems to me to be the pattern on which many of the South Sea stone adzes are formed."
These tools are thus described by Keate, from the Pelews:—"Their hatchets were not unlike those of the South Sea Islands, the blade part being made of the strongest part of the large Kima Cockle, ground to a sharp edge…. Uncouth as their hatchets might appear to our people, it was a matter of surprise to observe in how little a time the natives were able to fell a tree with them, though not without breaking several."
Torres Straits Islanders made their own shell hoes and digging sticks, as well as adzes and axes that were constructed from the shells of the giant clams.
Shell adzes are very efficient tools for cutting wood as some early witnesses reported from their travels to Pacific island locations. One account written in the 1800's wrote, "I noticed a large canoe being shaped by two or three workers with their sharp Tridacna shell adzes.----I saw they were going at it fairly rapidly; each blow of the shell adze sent fairly large chips of wood flying."
Shell adzes were made by percussion flaking and grinding. A piece of shell was extracted from the main shell by either direct percussion flaking or possibly by sticking against an anvil underneath as in bipolar percussion flaking. The final shaping and finishing work was done by either grinding the shell against a wet abrasive surface such as sandstone or by grinding against loose wet sand placed on a hard surface. There are two locations on a giant clam that produces the largest pieces of shell. One is at the hinge and the other is at the ribs. Sections cut from these locations provide the thickest pieces of shell and the largest adzes.
"Another recent find from East Timor (island state located about 400 miles northwest of Darwin, Australia) with a surprisingly early date is an edge ground Tridacna shell adze/axe found imbedded in the road surface near the township of Tutuala. A section of the adze was directly AMS dated to 8,600 +- 245 BP." 2006, Sue O'Connor, Uncovering Southeast Asia's Past, Selected Papers, Unpacking The Island Southeast Asian Package Neolithic Cultural Package, And Finding Local Complexity, p. 81.
"Large heavy Tridacna and Hippopus shell adzes are found in Golo Cave on Gebe Island (Indonesia) in levels dating to between 13,000 to 8,000 BP and adzes of comparable age and form have been found in Pamwak Cave in the Admiralty Islands." 2006, Sue O'Connor, Uncovering Southeast Asia's Past, Selected Papers, "Unpacking The Island Southeast Asian Package Neolithic Cultural Package, And Finding Local Complexity," p. 81.
"In Polynesia the Neolithic adze technology arrived in a well developed form with the first men to settle this Archipelago. There is no progression from simpler Pre-Neolithic forms." 1970, Roger Duff, Stone Adzes Of South East Asia, p. 7.
"Tridacna shell adzes were in use on Manus (island, province of Papua New Guinea) on evidence from the Pamwak site 7,000 and possibly up to 10,000 years ago." 2006, Wilhelm G. Solheim II, Archaeology And Culture In Southeast Asia: Unraveling The Nusantao, p. 122.
"Duyong Cave, near the Tabon Caves of Palawan's western coast (Philippines) produced a "Neolithic Burial" with four Tridacna shell adzes and two different types of shell ornaments as well as other types of shell tools. The calibrated Carbon 14 date for the burial is 3,675 - 3,015 B.C. and 4,575 - 4,425 B.C. for a nearby fire hearth that also had shell debris associated with it" 2006, Wilhelm G. Solheim II, Archaeology And Culture In Southeast Asia: Unraveling The Nusantao, p. 120.
The giant clam, Tridacna gigas is the largest living bivalve mollusc.