Just a naked blade "Gassan Masanobu"
Blade length 37.4cm, thickness at the base 8mm, width 3.2cm
This is just a naked blade. It shows a typical style of Gassan blade in Koto period. This blade looks from 16th century.
Actually, it was put in a horrible mount made by amateur hand when we found it. Then, we decided to rescue it. The horrible mount was thrown away. And now we are planning to restore it putting in new shirasaya.
Steel
Of course, this blade is constructed in sandwich style what is common in Gassan blades in Koto period. The edge steel (core steel or shin-gane) is fine with compact layer. The outer steel (kawa-gane) is dim with ayasugi layer pattern.
Hamon is clear in the hardened part. And the temper line is made of small particles, and it blurs in the ji.
Tang
The inscription is not very clear. You can see the crescent mark above the peg hole. And clear letter of "Nobu" at a distance downward. Probably, there are two letters between the crescent mark and nobu.
NBTHK Hozon-Token paper. They guess the signature "Gassan Masanobu".
The blade is 100,000.yen in this condition. And we are planning further works. Those are
Habaki, copper or silver : 30,000.yen ~ 40,000.yen
Shirasaya : 40,000.yen
Polishing, sashikomi style or hadori style : 80,000.yen ~90,000.yen
So the price of the finished blade after restoration work will be added up to 250,000.yen ~ 300,000.yen.
Gassan is a famous school in Dewa province from 13th century to 16th century. They supplied swords to monk soldiers in the region. They named "Gassan" on their blades. Gassan is the mountain what they prayed as a symbol of Buddha.
(Mt. Gassan, view from Tsuruoka city, Yamagata prefecture.)