Polished Black Tourmaline Freeform thumbnail Size: 4" Across

Size: 4" Across

This transparency exposes the fine

An ideal choice for geology and crystal collectors

They are pretty dense and definitely interesting in both appearance and feel

This Moonstone sphere is beautifully polished to a smooth finish

Polished Black Tourmaline Freeform thumbnail Size: 4" AcrossThis is a polished black tourmaline Freeform. It's a naturally dark, opaque black color. You'll find that it has a smooth feel from being polished. Its hard to take a good picture due to the polish. An interesting fact about tourmaline is that it's a pyroelectric and piezoelectric mineral. This means it can generate an electrical charge when heated or when subjected to pressure. This property was actually known for centuries, with early Dutch traders