Pottery & Porcelain Marks – Triangle & Heart: Most marks of triangles and hearts were first used in the early 20th century, but a few appeared in the late 1800s. Few of these marks are elaborate; most have a simple line border that makes the shape, with names or initials inside and outside the border. Of the few heart marks, none have the name or initials inside. Companies in European countries were the almost-exclusive producers of pieces with these marks. Miscellaneous Square, Rectangle & Other Geometric Shapes Star & Sun