Sandstone slab, large Galena Zebra varieties are commonly recommended

Zebra varieties are commonly recommended as clean-up crews in bioactive terrariums

This piece also appears to have some small blade-like secondary crystals

or spots under magnification (you can see it if you zoom in on close shots

perched atop a large piece of black tourmaline (schorl)

Sandstone slab, large Galena Zebra varieties are commonly recommendedApprox size: 10 5 8 x 7 5 8" (12mm thick) Approx weight: 1367g (3 lb) The display side of the slab is polished; the reverse is unfinished and may have saw marks, uneven parts, or paler color. This flat polished slab of picture sandstone is made from Arizona Sierra sandstone sourced from central Arizona. Sandstone is a sedimentary rock composed of sand compacted and cemented together through geological processes, giving it a grainy texture. Sandstone