Dumortierite Tumble Dark

Polished dark Dumortierite tumbled stones with a deep navy to indigo-black colour and a high-gloss finish. These are a notably saturated, dark variety of Dumortierite — the colour ranges from deep steel-blue to near-black indigo, with visible fibrous or striated internal structure on some pieces where the mineral's natural crystal habit shows through the polish. Sold per stone, approximately 2.5–3cm.

Dumortierite is an aluminium borosilicate mineral that typically occurs in a massive fibrous form, giving it its characteristic silky or striated internal texture. Its deep blue colour is caused by iron and titanium substitutions within the crystal structure. It is often found in metamorphic rocks and is relatively uncommon as a tumbled stone, making it a distinctive addition to any collection.

Stone Details

• Mineral: Dumortierite (aluminium borosilicate)
• Form: Tumbled, polished
• Size: Approximately 2.5–3cm per stone
• Colour: Deep navy to indigo-black with subtle fibrous internal structure
• Finish: High-gloss polished
• Sold: Per stone — colour depth and internal patterning will vary

Colour saturation and visibility of internal fibrous structure will vary naturally between individual stones.