Black, Grey and White Natural Agate Heart Briolettes measure approximately 21x21mm up to 27x25mm in size, have a glass like luster, good cut with fairly symmetrical shape, excellent polish with some internal features of the striated stone reaching the surface, the gem bodies are multi-hues of black, gray and white agate in a linear formation within each stone for a beautiful striped effect on the strand of approximately 9 gemstones.