Aizu-to Tomo Nagura

Classification
Origin / Type: Fukushima Prefecture (Aizu region), Japan; natural medium-to-fine polishing whetstone (Aizu-to / 會津砥).
Role: Tomo Nagura / Slurry Stone.

Markings:
Rectangular Stamp: 會津砥 (Aizu-to / Aizu Whetstone).
Circular Stamp: 響 (Hibiki / "Echo" or "Resonance", (inspection mark).

Evaluation & Characteristics
Grit Range: Equivalent to ~3,000–5,000 JIS when generating fresh slurry; refines down significantly as particles break down during work.
Abrasive Action: Fast-cutting, friable dacite/igneous matrix that creates an active, creamy mud. It is ideal for breaking the glaze on hard finishing stones (Awasedo), kickstarting slurry on hard JNATs, or cleaning loaded surfaces without leaving coarse rogue scratches.
Kasumi / Finish Profile: Leaves a clean, even, semi-matte contrast on San Mai or clad blades without gouging the softer cladding.
Physical Condition: Lacquer sealed, Cleanly sawn rectangular cube with chamfered working edges, zero structural fissures, and crisp stamps intact.
Description
Dimensions: Approx.: 35 mm × 25 mm × 27 mm
Weight: 50 g
Color / Texture: Light grey-buff base with the characteristic fine, speckled "goma" (sesame) patterning typical of authentic Aizu strata.