"Quartered Rhombus", "Takeda Rhombus"
A Japanese "quartered rhombus" geometric pattern. Consists of a rhombus pointing downward/upward (resembling an upright diamond), divided into four smaller rhombuses by lines or breaks in the pattern. May sometimes occur as a repeating element in design.
The historical Takeda clan's family crest uses the same pattern for its simplified form, so this pattern is also sometimes known as the "Takeda-bishi" (Takeda Rhombus).