I would date this tsuba to the Azuchi-Momoyama period, though it is possible it could be from the early (shoki) Edô period also. (安土桃山時代と江戸初期時代).
The use of the double lozenge was very popular in the Momoyama period and was often seen on kimono and kosode and variations included tonbo and double lozenge, plants and double lozenge and other combinations.
Shôami tsuba from the Momoyana period have many similarities with both Owari and Kyo sukashi tsuba. They are distinguished by being slightly heavier than Kyo, and lighter than Owari in their design and construction. Shôami also have a wider or fatter seppa dai and the hitsu are more rounded. Older Ko Shôami can have elongated seppa dai and these are probably from the Muromachi period.
There is an identical tsuba in Sasano’s book Japanese Sword Guard Masterpieces from the Sasano Collection Part I that matches in size, iron, thickness and design.
The dimensions are 81mm x 80mm x 4.9mm (centre) and 5mm (mimi)
Thank you for reading