[Paper Review] Symmetries in Images on Ancient Seals

Sparavigna, Amelia Carolina|arXiv (Cornell University)|Sep 21, 2008

Image Processing and 3D Reconstruction4 citations

TL;DR

This paper investigates symmetries—bilateral and rotational—in images engraved on ancient stamp seals from Neolithic to pre-Columbian periods. Using visual analysis of archaeological seal collections, it demonstrates that seal base geometry (e.g., circular, ovoid, elliptic) constrains and shapes the symmetry types observed, with bilateral and two-fold rotational symmetries being most common. The study highlights antisymmetry and broken symmetry as culturally significant features, particularly in Pre-Columbian and Egyptian seals, suggesting symbolic or protective intent beyond aesthetics.

ABSTRACT

We discuss the presence of symmetries in images engraved on ancient seals, in particular on stamp seals. Used to stamp decorations, to secure the containers from tampering and for owner's identification, we can find seals that can be dated from Neolithic times. Earliest seals were engraved with lines, dots and spirals. Nevertheless, these very ancient stamp seals, in the small circular or ovoid space of their bases, possess bilateral and rotational symmetries. The shape of the base seems to determine the symmetries of images engraved on it. We will also discuss what could be the meaning of antisymmetry and broken symmetry for images on seals.

Motivation & Objective

• To analyze the presence and types of geometric symmetries in images on ancient stamp seals across different cultures and time periods.
• To investigate how the physical shape of the seal base (e.g., circular, ovoid, elliptic) influences the symmetry of engraved designs.
• To explore the cultural and symbolic significance of antisymmetry and broken symmetry in seal iconography, particularly in Egyptian and Pre-Columbian contexts.
• To propose a new analytical framework for studying seals through symmetry, emphasizing their role in archaeology and cultural meaning beyond mere decoration.
• To stimulate further research into the absence of symmetry in certain cultures, such as the Indus Valley, as a meaningful cultural phenomenon.

Proposed method

• Visual analysis of engraved images from documented seal collections, including those from Çatalhöyük, Mesopotamia, Egypt, and Mesoamerica.
• Classification of symmetries based on geometric transformation: bilateral (mirror), two-fold, four-fold, and higher rotational symmetries.
• Comparison of seal shapes (e.g., round, oval, rectangular, cowrie-shaped) with the symmetry types present in their engravings.
• Use of archaeological and museological sources (e.g., Egyptian Museum of Turin, Berlin Museum) to identify and contextualize symmetrical patterns.
• Interpretation of antisymmetry in paired figures (e.g., predator-prey, twins) as intentional design choices with symbolic or functional intent.
• Cross-cultural comparison to assess patterns in symmetry use and exceptions (e.g., Indus Valley’s avoidance of symmetry).

Experimental results

Research questions

• RQ1 How do the geometric shapes of stamp seal bases constrain the types of symmetries found in their engraved images?
• RQ2 To what extent are bilateral and rotational symmetries present in Neolithic and ancient Near Eastern stamp seals, and what does this suggest about early artistic and cognitive preferences?
• RQ3 What symbolic or functional meanings might antisymmetry and broken symmetry convey in Pre-Columbian and Egyptian seals?
• RQ4 Why are three-fold and higher rotational symmetries rare in Egyptian scarab seals, despite their presence in other contemporary art forms like faience pottery?
• RQ5 What does the absence of symmetry in Indus Valley seals imply about cultural attitudes toward balance and order in material culture?

Key findings

• Bilateral and two-fold rotational symmetries are prevalent in stamp seals, especially those with elliptic or circular bases, indicating a strong link between seal form and symmetry type.
• Four-fold rotational symmetry is observed in round stamp seals with geometric patterns, such as spirals and rosettes, suggesting intentional design for visual motion and balance.
• Egyptian scarab seals with coils and spirals frequently display bilateral and two-fold rotational symmetry, possibly enhancing their protective function as amulets when rotated.
• The Egyptian Museum of Turin houses a unique cowrie-shaped scarab with two human figures in bilateral symmetry, dating to 2200–2040 BCE, indicating symbolic twinhood or duality.
• Pre-Columbian Taino round seals exhibit four-fold rotational symmetry, while rectangular seals favor bilateral and two-fold symmetry, reflecting shape-driven design constraints.
• The absence of three-fold and higher rotational symmetries in most Egyptian scarabs is attributed to the elliptic shape, though such symmetries appear in round button seals and faience pottery, suggesting cultural and technical limitations in application.