Boniosz 5lb Black Horticultural Lava Rock Soil Additive for Cacti, Vase Fillers, Succulents and Terrarium Plants - No Dyes or Chemicals - 100% Pure Volcanic Rock is up for auction in Patio, Lawn & Garden. The current bid is $4.50, 76% below the $19.00 MSRP, in New/Like New condition. This auction has ended — similar items appear in live auctions regularly.