What is Mokume Hada in Japanese Katana terminology?

Mokume Hada or 杢目肌 in Japanese, refers to a type of pattern on the surface of the ground iron (jigane) of a Japanese sword. The term ""Mokume Hada"" refers to a pattern that resembles the grain of burl wood, specifically the rings of a tree.

This pattern is created during the ""Orimodoshi Tanren"" (折り返し鍛錬), a process of repeated folding and forging. In this process, the ground iron is folded in multiple directions, which results in the beautiful Mokume Hada.

In most cases, the pattern is not purely Mokume Hada, but a composite state mixed with Itame Hada (wood grain skin). This is because the process of folding and forging often results in a mixture of different patterns.

Furthermore, when the Mokume Hada is prominently visible, it is sometimes referred to as ""Kinowa Moku"" (樹輪杢) or ""Jorin Moku"" (如鱗杢).

- ""Kinowa Moku"" literally translates to ""tree ring burl"", indicating that the pattern resembles the rings of a tree.
- ""Jorin Moku"" literally translates to ""like a scale burl"", indicating that the pattern resembles the scales of a fish.

The pattern of the ground iron (jigane) plays a significant role in the aesthetics and value of a Japanese sword. It is one of the factors that sword connoisseurs look at when evaluating a sword. The Mokume Hada, with its pattern resembling the grain of burl wood, is a distinctive feature that sets the sword apart.