meaning of „lettene“?

Question

The word „lettene“ appears in Thomas Mann's „Joseph und seine Brüder“ (in subchapter „Das Kind der Höhle“ of Chapter 3 „Die kretische Laube“ of the last part „Joseph, der Ernährer“). The paragraph reads like this:

»Dieser Knecht«, antwortete Auta, indem er mit einer Hand die lettene Figur umwickelte und die andere gegen den König aufhob, »wird es genau machen, wie Pharao gebietet und es mich zu meinem Glück gelehrt, – der Einzige des Rê, das schöne Kind des Atôn.«

(Auta is a sculptor, and the „Figur“ is a statuette he has made of the Pharaoh's sister, „die süße Prinzessin Baketatôn“.)

A thorough web search has revealed absolutely nothing of relevance.

I don't believe this is a typo because this passage is identical in two different editions of the novel (Aufbau-Verlag 1956 and Fischer Klassik 2009).

The Russian translation conveys the „lettene Figur“ as „глиняную фигуру“, i.e. „the clay figure“. Can I take it that „lettene“ means „made of clay“?

Answer 1

Grimms Wörterbuch provides for substantive Lett(en):

Lehmerde, thonige Erde, thoniger Mergel (todays orthography would require th to be replaced by t)

so it means something like clay or marl, so the Russian translation seems correct. I have never encountered that word, however, so the frequency indication of DWDS may be a bit exaggerated.