Izariyama Tomae #C_IZR_4_2

Description & Mine Provenance
Type: Awasedo (finishing stone).
Mine Origin: Izariyama (イザリ山), a renowned western-cluster (Nishimono) mine in the Kameoka/Tamba district of Kyoto.
Dimensions & Weight: 205 mm × 80 mm × 45 mm; 1,772 g (heavyweight full bench size with exceptional thickness and a broad working footprint).
Markings & Stamping:
Features the 正本山 (Sho-honyama) verification stamp, certifying origin under the Kyoto awasedo standard.
Stamped with the traditional Kyoto Stone Association cherry-blossom inspection crest (Kansen mark).

Notable Physical Features on the Underside
Arched Saw Marks: The wide, sweeping radial grooves across the face are classic quarry or workshop saw marks from large circular diamond/carbide stone-cutting wheels. They show the block was slabbed mechanically rather than split strictly along natural bedding planes, leaving the base rough for mounting grip.
Incomplete Stamp Transfer: The ink is broken up precisely because it was stamped directly over those saw ridges. The ink only transferred on the high ridges of the saw teeth, leaving the valleys dry.
Edge Cleave / Chip: On the right edge (visible in the wider shot), there is an older, naturally patinated edge breakout. It follows the stone’s internal cleavage angle and is completely stable, showing no spiderwebbing fractures running inward.
Oxidation Spots (Sabi): The scattered rusty orange-brown spots are small, localized iron mineralizations common in Izariyama and related western/southern Kyoto strata. They are superficial and benign.
Base Flatness & Grip: Because this side is grooved and unlapped, it provides great mechanical tooth
Coloration & Aesthetic: Pale greenish-grey Asagi tone with subtle buff-tan undertones, accompanied by characteristic light iron flecking (Nashiji points) on the bottom face.
Classification & Layer
Stratum: Tomae (戸前) layer, exhibiting a tight, uniform sedimentary structure characteristic of high-grade Izariyama finishing beds.
Fineness: Fine finishing/polishing grade, roughly equivalent to 8000+ grit depending on slurry density and Nagura usage.
Hardness: Rated at approximately Lv 3 to 3.5.  yielding crisp edge apexes and clean, hazy contrast on bevels.
Evaluation & Working Utility
Form Factor: Sawn square with flat, parallel reference surfaces; the 80 mm width comfortably supports wide kitchen blades, carpentry plane irons, and chisels without overhang instability.
Service Life: Massive 45 mm thickness ensures an heirloom working lifespan suited for heavy shop use.
Abrasive Feel: Smooth, consistent feedback with high cutting efficiency for its density; initiates best when paired with an Atoma diamond plate, tomo nagura, or fine slurry stone.
Condition & Flaw Inspection
Surface: A faint diagonal line crosses the face; appears completely non-toxic, but should be examined periodically, and if needed, chamfered or smoothed to guarantee zero tool catching.
Edges: Natural micro-chipping typical of dry-sawn strata around the corners; beveling the outer perimeter before regular water immersion is advised.
Sides and base are sealed with water based polyeurithane lacquer to prevent water intrusion along the sedimentary planes.
Market Valuation