Examination of a Bronze Age Spindle Bottle: Determination of Age, Provenance, and Contents

1. Examination of a Bronze Age Spindle Bottle:Determination of Age, Provenance, and Contents Gary W. Carriveau Lyncean Group 26 May 2010

2. Introduction Red lustrous wheel-made spindle bottles found in the Levant, Cyprus, and Egypt have received a good deal of attention in the archaeological literature. This presentation deals with one example of this type of vessel and attempts made to understand more about it.

3. Examples of Spindle Bottles

4. Background Spindle bottles are well known from excavations in the Eastern Mediterranean and from depictions shown in Egyptian tomb drawings. In some tomb drawings from the Eighteenth Dynasty ( 1540-1307 BCE ) they are shown as objects brought as trade or tribute to the Egyptian court.

5. Bottle excavated from the Amuq Valley (SW corner of modern Turkey). Considered as evidence of a long historical sequence of trade. The burnished red spindle bottle “probably contained honey or wine”; these bottles were standard trade items in the Eastern Mediterranean. . From Excavations

6. Excavated Bottles These two examples show the characteristic shape. It is believed that the long neck would prevent evaporation and the small round spout may also prevent spillage.

7. Tomb Drawings

8. Tomb Drawings

9. Stern’s Bottle Photo The label reads: “Terra Cotta Amphora Upper Egypt of the Greco- Roman Period…a pitchy substance and probably viscera of a mummy. Frederick Sterns’ Collection”

10. DIA Details • Acquired by a private collector while in Egypt in the 1890’s with no known provenance • In the permanent collection of the Detroit Institute of Arts for about 100 years. • Handle broken off and the vessel is cracked and has leaked a gummy black material through the crack • Probably stored on its side for some time

11. Why Proceed? Although there is the lack of documentation (provenance and history) for this object, technical examination may provide some useful general information. The origin of these bottles as well as the exact nature of their contents is still the subject of scholarly question and debate.

12. Age Authentication The first step in the investigation was to authenticate the age of the object. Because we are dealing with a single example with no find spot, no original provenance information exists. There are many forgeries on the art and antiquities market. It makes little sense to put a large effort into analysis of a “fake”.

13. Age Determination “ And I brought it to a dim glow by taking it to bed with me and placing it on a warm part of my bare body” Sir Robert Boyle Proc. Of the Royal Society, London 1672 THERMOLUMINESCENCE (TL): phosphorescence developed in a previously excited substance upon gentle heating

14. TL Dating • Determination of age by measuring the effect of the accumulated radiation dose since the crystalline minerals in the object were last heated • Ceramics contain appropriate minerals • Radiation dose comes from the fabric of the ceramic object and the environment to which it has been exposed • Radioactive material in the fabric of the object, the surrounding, and cosmic radiation contributions are all considered

15. TL Dating Fundamentals • Manufacture (firing) erases geological accumulated effects thereby setting the “clock” to zero • A small sample (few mgms) is heated and the visible light is measured with a PM tube: the TL signal as a function of temperature, also known as the “glow curve” • The TL effect is quantified with the application of a series of known and controlled radiation doses and subsequent TL measurements with similar samples

16. TL Dating Fundamentals • “Equivalent dose” is determined by comparing the measured TL signal (from the glow curve) to the measured TL response per unit dose “Age” = equivalent dose/dose per year

17. Annual Dose Determination • U, Th, K, Rb from vessel fabric Calculated dose per year (per ppm) U=255 mr Th=72 mr Rb=0.04 mr K(%)=83 mr Estimate for “typical” ceramic~500-700 mr/yr • Gamma ray contributions from the environment where the vessel is located or stored • Cosmic radiation

18. TL Dating Results TL Results: Stern’s Spindle Bottle Age=3667+900 BP 1657+900 BCE (18th Dynasty is from 1540-1307 BCE ) The error bars in this determination are rather large because the object has no known provenance or history. This leaves a rather large uncertainty in the annual dose rate because of the error bars associated with the dose per year calculation. However, the results indicate that the object was manufactured in antiquity.

19. Question of Place • Literature indicates that Spindle Bottles possibly came from a number of places including Cyprus, Turkey and Egypt; where was this example manufactured? • Provenance studies have been a basic tool of archaeologists for centuries – based on stylistic criteria as well as (more recently) compositional analysis of the material used to manufacture the object

20. Neutron Activation Analysis I decided to use neutron activation analysis to determine the elemental composition • A small (10’s of mgms) sample is sealed in pure quartz and exposed to the intense neutron field near the core of a reactor • After neutron activation the decay gamma ray spectra are measured and elements and their quantity are determined – this provides an elemental “fingerprint”

21. BNL Database Through the use of multivariate analysis programs the measured elemental “fingerprint” can then be compared to an extensive database developed for over 40 years at the Brookhaven National Laboratory in collaboration with archaeologists working around the world

22. Trace Element Study List of elements used in this study were: Na Cs Cd Ba Sc Tb La Ce Eu Hf Th As U Ta Br Fe Co Cs Sm Cr Yb Lu K

23. Provenance Results Comparison of Stern’s Bottle NAA trace element concentrations with the BNL data base shows: • Material in Stern’s Bottle is unlike any known examples from Egypt • Material in Stern’s Bottle shows a good match with material from objects known to come from the archaeological site of Idalion, Cyprus

24. What is Inside? Label indicates “..pitchy substance and probably viscera of a mummy.” The published literature indicates that these bottles were thought to be used as containers of oils, unguents, perfumes, wine, honey, ???? No published literature on the determination of bottle contents

25. X-Radiographs Rotation: 90 degrees between right and left image

26. Neutron Radiography Exposure performed At the University of Michigan - Phoenix Research Reactor

27. Core Extraction • A thin-walled tube (ID ~5mm) was pushed directly down along the axis of rotation • The tube was removed and a rod was used to push the core sample from the tube • Compression of the core could not be avoided but the spatial relationship from top to bottom was preserved

28. Core Material Core extracted from the middle of the vessel, along the axis of rotation

29. Core Segment Enlargement of the soft, viscous portion of the core

30. Core Segment Enlargement of the grainy, “dry” portion of the core

31. Sample Preparation • The core was divided into 30 samples, 1-2 mm length each • Each section was dissolved in dichloromethane and filtered through filter paper separating solids from liquid • The weight of the solids in each sample was determined • The core and organic liquid had a characteristic odor

32. Solid Fraction Micrograph of the sand crystals after cleaning with HF acid XRD confirmed silicon sand

33. GC Sampling • Following evaporation of the original solvent the organic residue was re-dissolved and treated to produce methyl esters of any fatty acids present • The ester containing samples were then individually analyzed using a GC with a 60 meter column

34. GC Results Representative GC results of extracted core material with major peaks identified as myristic, palmitic, and stearic acids

35. GC Results • The major constituents from the GC results indicate palmitic and stearic acid are present (this corresponds with information gained on the source of the characteristic odor) • Myristic acid ester was also found in small quantities

36. Core Results There seems to be two layers: the bottom (samples #2-#15) with larger average amounts of sand and a P/S ratio of ~4 and samples #23-#28 with a P/S ratio of ~7 and a smaller amount of sand except near the top of the core sample.

37. Ratios Palmitic and stearic acid ratios (left side) And relative sand content (right side) of core segment samples

38. Discussion of GC Results • The P/S ratios and presence of myristic acid in the samples can limit the number of possible oils that should be considered • The upper section (P/S ~7) was probably palm oil or olive oil

39. Discussion of GC Results • Results from the bottom section (P/S ~4) suggests oil from almond, olive, safflower, palm kernel, goose, liver, or milk. Safflower oils containing myristic acid are from India and Canada. Oil from geese contains more myristic than stearic acid. Almond oil containing myristic acid is from “temperate” climates. This suggests limiting the possibilities to oil from olive, palm kernel, liver, and milk.

40. Summary • The thermoluminescence test results show that the Stern’s bottle was manufactured in antiquity • Comparison of the trace element “fingerprint” from neutron activation analysis with the BNL database shows that it is unlike any tested Egyptian material and suggest that it was most likely made in Cyprus

41. Summary • The bottle does not contain viscera but contained some type of natural oil (most probably palm or olive) consistent with material likely to be found carried in bottles of this type • The information produced in this study cannot be used to explain the presence of beach sand

42. Acknowledgements The Phoenix Memorial Laboratory Nuclear Reactor group, University of Michigan The Egyptian Art Department, Detroit Institute of Arts The Chemistry Department, Wayne State University

43. . Thank you for your attention. I am happy to try to address and answer any questions that you may have. Gary W. Carriveau gary_carriveau@yahoo.com