Here is a colourful collection of Necklaces . I grouped these together because of the various colours 

There is a mix of multi coloured glass beads , a plastic necklace and a couple made from dyed tumbled sea shell pieces, one has square mother of pearl pieces. But I draw you attention to the top left necklace which looks very much like it is made from semi precious stones this is the reason for a high resolution photo of some of the beads .There looks to be agates and milky and pink quartz beads and a dendrite bead too, so it could be a mix of glass and semi precious stones .There is a maker`s tab that looks like a V