Thank you for viewing. This was attached to a K18 pendant. Size: Approximately 14.5mm x 7.1mm Please allow for some margin of error. Please refer to the photos for details. I would be happy if you could use it for pendant heads, necklaces, rings, etc., for handmade or custom jewelry. Since this is a layman's inspection, there may be oversights. Please purchase only if you do not mind minor details and understand. As it is a natural item, there may be dullness, unevenness, dimples, wrinkles, etc. Please purchase only if you understand that this is a used item and has been stored at home. Please understand that there may be oversights. Those who are looking for perfection or are very sensitive to details should refrain from purchasing.