Dark Purple Sea Glass
This sea glass color is a dark amethyst purple with some variations. Most of the dark purple sea glass found in Puerto Rico comes from antique Windows.
During the Victorian era Puerto Rican houses often had several small window panes of colorful patterned glass. They were used in a range of colors including dark purple, torquoise, reisling blue, cobalt, red, green-blue, amber and white. Most of the dark purple sea glass I have found there are flat pieces with these window patterns embossed on them.