Purchased from a collector. I was told it's a Jomon period magatama (comma-shaped bead), but the exact excavation site is unknown. I am selling it as my collection has grown. I think you can see how well it transmits light if you look at the photos. As you can see in the fifth photo, when I shine a light directly on it, it glows too much (my fingertips disappear), making it difficult to photograph. So, I took the second and fourth photos with the light slightly off to the side. Even then, the magatama is still emitting plenty of light. This listing is for the magatama itself only; the box is not included. Thank you for looking.