Let the obsidian and hematite remove negativity...10mm, and fits 7.5in (19cm)in to 7.75in(19.7cm)Item 185- Hematite,obsidian w/crackle$30.00PriceQuantityAdd to CartRETURN AND REFUND POLICYPlease send item back in original package within 15 days for full refund.