Subject:Re: Jade grit/tool marks
Posted By: Super Tue, Oct 22, 2013
I must applaud Adam's willingness to share his "study of jade tool marks" article with others and the enthusiastic responses of many jade lovers to his offer. That speaks well of jade collection and jade collectors/lovers in this forum.
I do not know if the article that was offered by Adam is this article:
"The identification of carving techniques on Chinese jade
Margaret Sax, Nigel D Meeksa, Carol Michaelsonb, Andrew P Middletona"
which was sponsored by the Department of Conservation and Scientific Research, British Museum. We had some discussions regarding it a while ago.
Ms. Sax also wrote another article:
"The technology of jades excavated at the Western Zhou, Jin Marquis cemetery, Tianma-Qucun, Beizhao, Shanxi province: recognition of tools and techniques"
which may be another interesting read.
Roger said,"The study by the British Museum only confirms the tools and methods used to carve jade prior to the 20th century and as desribed in nearly every jade study in the past 100 years.
When we refer to tool marks on a jade piece reputed to be 19th century or earlier, we are talking about the mark of POWER tools. Slippage is the most common mark by a power tool and almost impossible to make with the the old hand tools. The slow and tedious working with a hand tool required many hours of repeated strokes in the same path and could never create the slippage mark of a power tool."
I am not disagreeing with what he said (at least not yet until I can understand more regarding what he tried to say).
I would like to ask him to please clarify:
(1) What did he mean by "power tools? Powered by what, electricity, hand or foot? In what period in China were "power tools" being used in the "carving" of jades?
(2) What is his definition of hand tools and from what period in China only "hand tools" were being used in the "carving" of jades?
Please understand that I am not showing disrespect to his statements because I am a jade amateur myself and the more I learned about jade the more discouraged I had become because I found out there were a lot about jade that I still do not know and may never be able to really learn due to my limited resources.
This was what one forum member said about Sax's first article:
"Powered tools have been used for thousands of years.
A spinning motion is created in a number of ways,
With a bow and string that when moved back and forth spins the shaft on which the tool tip has been added., or foot powered wheels similar to a treadle which then rotated the tool.
Each of these tools leaves a signature in the jade. The article shows through the use Scanning
Electron microscope images, how to identify
each of these methods of carving. The illustarations are very clear."
"Professor S. Hansford said rotary tools used in wheet-cutting were not invented until the Iron Age because bronze is simply not hard enough to be used as rotary tools. However, tu (disc type) made of stone or other non-metal material were used during Neolithic time and Mr. Boda Yang did say rotary "powered" tool (or tool machine) were found during early Chinese dynasties (not powered by foot, but powered by hand). Therefore, it was indeed very difficult to understand tool marks or jade working tools that were available during archaic time. We must define exactly what "power tools", "rotary tools". "rotary tool machine" are before we can even discuss jade working techniques of tools."
"according to Prof. S Hansford, the quality of the working techniques shown on jade carvings, some time did not truly depend on the jade working tools or even truly reflect their true ages, but simply depend on the skills of the artisans. Therefore, holes drilled at Neolithic time by bamboo drill can be better than those made later with metal drills. On the other hand, some modern jade carvings, made with electrical high speed jade working tools can be made better in quality than those that were made at ancient time. For example, if you look at some of the Cu Da Ming (Ming dynasty carvings) jade carvings, that seem to be made very crude and poorly (they did not focus in details) but they would be indeed ancient Chinese jades."
Also, please remember that whether jade carvings were made with modern powered tools, ancient hand/foot powered tools or hand tools, very often you will not see any tool marks on them.
Therefore, while it will be helpful in learning more about tool marks, unfortunately using tool marks alone in the determining of the age of a jade carving can indeed be inconclusive.
Thanks in advance.