A signature seal. Looks like it was never used.
Clear plastic, (we think) pretty sure it's not glass. Too hard to carve.
It's unusual in that we haven't seen clear ones before.
It's 2 inches long and 5/8 inches thick
We have been selling Japanese antiques for 25 years. We are shipping from Los Angeles.
We have other antique/vintage Japanese items on our eBay site.
We will combine items for shipping.