Incredible necklace from estate sale

Beautiful necklace. Gorgeous blue and silver. This is a heavy necklace, bought at an estate sale. I do not know if it is real silver, plated silver or faux silver. I do not know what the blue part of the necklace is but it may be glass or very hard platic. The necklace is on a ribbon which is either a very dark blue or black. Very well made striking piece. Clasp on back is standard necklace clasp . The blue shows different with different colors. I have not edited any of the pictures and they were taken outside. Blue sometimes look lighter and sometimes darker. I have worn this with white and it is incredible. I do not know what the original price was as I bought it at an estate sale.