There are all kinds, mainly etched with a tiny design on one side which is left unetched, or shiny. I do like them, and I hope one day they will find a good home with someone who will treasure them as much as I do.
The reason why I remembered these beads today is because I made a little necklace that consisted of three beads:
BUT there is one other side to this story: in "The Demi-Monde: Winter", the first of the quadrology that Rod has written, there is a tiny episode, where Norma, one of the main characters, is surrounded by the bad guys, and "...The Witchfinder wrenched off the 'I (heart) Blood' necklace Norma was wearing, sending the glass beads skittering over the frost-hard cobbles."... Well, this is the necklace that went into the book!