*4.3. Indirect Evidence for a Purple Dyeing Industry in the Aegean Sites of Thera and Rhodes*

Although there is strong evidence for relating the purple color in the Theran and Rhodian contexts, with the Late Bronze Age industry of purple dyeing, there are no conclusive data for the location of the dyeing workshops, since there is not yet evidence of such installations in the excavated parts of the settlements. Instead, we present here only a number of strong arguments that support their possible existence outside the excavated sections, which correspond to residential areas.

The significant quantities of seashells found, most of them fragmented, in different buildings and streets at Akrotiri [66], corresponding to the stratigraphic and chronological sequence of the Late Cycladic I period, are considered food refuse, as the probability that dyeing installations existed near an inhabited area is highly unlikely. The largely attested second use of the shells in many instances as construction material for the floors of many rooms (Xeste 3, Pithoi Storeroom A2, B6 inter al.) [67] (pp. 195–196), (Figure 6), [68] (p. 124), as well as in mortar, as a filler in pottery production, etc., could more likely be associated with systematic recycling of waste products from the purple industry, with organized food scrap collection being less likely [66,69] (Figure 4), [70] (pp. 43, 44), (Figures 5 and 6), [5,71,72]. In another context, the evidence for the second use of murex shells, without indication of whether they are remains of foodstuffs or dyes, either in the production of lime plaster or in pieces visible on plastered surfaces probably to strengthen floor beddings, is discussed extensively in [73].

However, the murex finds (mostly *M. trunculus*), in fact crushed, whether food debris or used as construction material or as a filler in pottery production, etc., dating to the Late Cycladic I/Late Minoan IA period, are proof of familiarity with the molluscs, implying the existence of a murex purple-dye industry at Akrotiri [5,72,74].

The lumps of mollusc purple found at Akrotiri together with lumps of other pigments in the same contexts could be intended for painting. The identification of mollusc purple pigment on murals at Akrotiri [22,75] and Raos [42] suggests its most probable application in monumental painting on Thera. The pigment was used selectively on the wall paintings. It was applied on certain petals of the rosettes in the "Rosette and Lily" wall painting from the Raos residential building. It was also used to render the petals of the crocus flowers, a necklace, and many details of the richly adorned female garments, and snoods in the wall paintings of the "Saffron Gatherers," the "Procession of Women with Bouquets," and the "Adorants" from Xeste 3 at Akrotiri [22].

The use of purple in the women's costumes implicitly refers to a possible second (or probably first) application of the purple color on Thera, the dyeing of textiles. In addition, textile production would have been quite a flourishing activity at the site, given the numerous loom weights found there [76–79]. All this evidence from Thera, both scientific (physical and chemical identification) and iconographic, reinforces the view that there was murex purple dye production on the island.

Excavations conducted since 1984 in the prehistoric settlement at Trianda on Rhodes have yielded evidence of a rather frequent use of *M. trunculus* in the settlement, not only by their sporadic presence along with other finds associated with food consumption, but also by the large quantities of crushed shells used either for reinforcing lime plaster or for constructing a strong substrate for plastered pavements, as in the case of the polythyron in the Markos plot [38]. On the other hand, many pigments, mostly red or pink and in some cases blue or white, were found in lumps or in powder form inside vases, mainly conical cups, or even without containers. Consequently, some of the above pigments might had been used by the painters, itinerant or local, who created the amazing frescoes that decorated the Late Bronze Age IA and even the earlier buildings at Trianda. Most recently, many lumps of pink pigment and pigments of other colors were found in the Middle Bronze Age levels of the settlement. Shiny red plasters decorated the houses of the settlement during this early period [36]. A deposit of thousands of murex shells, found in an open area close to a Middle Bronze Age polythyron, recently revealed during the excavation of the Atsiknoudas plot [80], south of the main Late Bronze Age city, provided further evidence of the early technologies and the activities of the society at Trianda, before the Minoan expansion. Moreover, the presence of many loom weights in an area east/southeast of the main settlement suggests large-scale textile production [36], which might be connected with dyeing as well. However, the only purple production workshop excavated thus far on the island of Rhodes is the Hellenistic installation found in the town of Rhodes, south of the Hellenistic fortification wall [81].

#### **5. Conclusions**

Lumps of mollusc purple pigment of similar physical appearance have been excavated at the Aegean sites of Akrotiri on Thera and Trianda on Rhodes dating from the Early Late Cycladic period. The same pigment was identified in purple details of certain wall paintings at Akrotiri and Raos, on Thera.

The chemical composition of the purple pigment was identified with molecular spectroscopies, microRaman and FTIR. It consisted of a calcium carbonate substrate to which the shellfish purple dye was adsorbed, possibly by immersion into a dye bath. The calcium carbonate substrate of the pigment, consisting mainly of aragonite and calcite, put in evidence its shell origin and referred to the "recycling" of shells of any species. The HPLC profiles collected from the archaeological samples were all similar, as they contained the same indigoid compounds in a comparatively similar relative content. MBI, DBI, and DBIR were recorded to be in the majority, whereas IND, 6 MBIR, and 6MBIR were present in much lower proportions.

Although there is not yet direct evidence for the location of purple dyeing installations in the Theran or Rhodian Late Bronze Age contexts, there are several arguments presented in this work that allow for the purple color identified in Akrotiri and Raos on Thera as well as in Trianda on Rhodes to be related with the Aegean Late Bronze Age industry of murex purple dyeing. The deposits of murex shells as well as the largely attested second use of the shells in many instances at Akrotiri and Trianda could more likely be associated with the systematic recycling of waste products from the purple industry than with an organized deposition of food debris. In addition, the large-scale textile production suggested by the numerous loom weights found in both sites might be connected with dyeing as well. Finally, the use of the purple pigment analyzed in this paper in several scenes in the Xeste 3 wall paintings at Akrotiri to render with naturalism not only the purple petals of the crocus flowers but also several details in women's woven costumes implicitly reinforces the probability of a local purple textile dyeing industry at the beginning of the Late Bronze Age.

**Author Contributions:** Conceptualization, S.S.; analytical methodology and investigation, S.S., I.K. and K.S.A.; archaeological context, T.M., K.B. and M.M.; writing—original draft preparation, review and editing, all authors. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Data available on request from the authors.

**Acknowledgments:** The authors would like to thank Christos Doumas, Director of the Excavations at Akrotiri, Thera, for permission to publish and support in studying the archaeological material from the settlement at Akrotiri. MicroRaman measurements were carried out in the Laboratory of Dynamics, Interactions and Reactivity LADIR, UMR 7075 CNRS/UPMC, Campus CNRS, Thiais. Special thanks are due to Ludovic Berlot-Gurlet for his valuable assistance. The main corpus of analytical data obtained with HPLC and FTIR techniques was produced and elaborated during previous affiliation of the first, second, and third authors to the Ormylia Foundation, Art Diagnosis Centre.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**

