Lianna Spurrier Publishes UNTANGLED: A Die Study of Keicho Ichibu

This work presents the first comprehensive die study of the Keicho ichibu, a rectangular Japanese gold coin minted from 1601 to 1695. Spurrier analyzes 306 specimens-including auction records, museum holdings, and reference-site images-to reconstruct how dies were made, shared, and reused across mints and time periods. The study proposes a new three-phase chronology (early, intermediate, late) based on the position of the character ?, the arrangement of border dots, stylistic features of the inscriptions, and the overall quality of manufacture.

Spurrier also redefines the traditional calligraphic attributions, replacing the historical Kyoto/Suruga/Edo classifications with neutral letter-groups (K, S, E) and identifying three rare subsidiary handstyles (H, U, Y). Extensive die maps show how A- and B-side dies pair across hundreds of examples, revealing patterns of reuse, sequencing, and cross-type relationships.

A major contribution of the book is documenting how certain Keicho ichibu were struck over earlier Gaku ichibu issues, especially in the earliest phase, supporting the historical transition from the earlier form into the Keicho series. Spurrier also demonstrates that ryohon ("double-hon") coins-those bearing two ??? marks-show signs of being more carefully struck, with cleaner edges, fewer circulation marks, and higher rates of complete border impressions. Combining statistical analysis and die-link evidence, she suggests these may have served a ceremonial or presentation function rather than normal commerce.

The study concludes with comparative rarity tables, mint-location indicators, pricing trends, and a detailed set of appendices including typical examples and full die maps, offering the most technically rigorous examination of Keicho ichibu dies to date.

Link to UNTANGLED: A Die Study of Keicho Ichibu on Newman Portal:
https://nnp.wustl.edu/library/booksbyauthor/529486

Link to Lianna Spurrier's site on Japanese bar money:
https://rectanglecoins.com/