Natural Crystals: Cut & Polished Puff Heart

Formula: Ca₂B₅SiO₉(OH)₅  Colour: White, colourless, brown Lustre: Sub-Vitreous Hardness: 3½ – 6½ Specific Gravity: 2.53 – 2.59 Crystal System: Monoclinic. Please note Howlite is a soft porous stone that is naturally white with some thin grey veining and is often dyed to look like other more valuable gemstones such as Turquoise, Lapis Lazuli and Malachite. The dye can run and will fade. We do not choose to stock any dyed Howlite.