Would like to identify vintage tile
My house was built in 1948. Though the house is generally postwar-zero-style-but-plenty-of-character, the fireplace surround is rather dramatic: It's made of glossy, claret-colored ceramic or porcelain tile (6" x 6") that has straight ripples in it, six ripples per tile. I saw tile like this one other time, on the front of an old movie theater in Seattle (I think it was green, though). I'm the second owner of this house, and while the previous owners maintained it well, they changed/updated almost nothing, so I believe this tile is original, though I can't be sure. I've searched the Internet using every search cue I can think of, looking at countless tile photos, but I haven't happened upon it yet.
Does this description sound familiar to anyone? I'd love to know what "sort" of tile I have.