These rectangle beads look more like an hourglass or bone-shaped beads with the indented center.  Ends measure 9mm and middle measures 7mm.  All beads consist of various amount of yellow swirls around the bead with splotches of cloudy white. 

The striping does not show up very well in the photos but it is noticeable in some pictures.  Also color in the photos is a little more vibrant than the actual that is more subdued. There are 16 beads on this strand.

 All design elements are subtle and overall create a delicate looking strand of beads.

My vintage beads were purchased mostly from a vendor in Tucson who was selling his grandmother's collection.  I am not an expert of vintage beads so have no information of materials or techniques used.  I picked them out because they were sometimes very pretty and sometimes whimsical and different.