Datolite is a rare calcium boron silicate, distinguished by complex equant crystals and pale yellow-green hues. The Huanggang skarn deposit in Inner Mongolia is the modern type-locality for collector-grade datolite – sharp, gemmy, often with co-crystallized ilvaite or fluorite.
Key Facts
- Mohs hardness 5-5.5 – softer than quartz, harder than fluorite.
- A boron mineral – important indicator for B-rich skarn assemblages.
- No cleavage; conchoidal fracture similar to quartz.
- Huanggang (Inner Mongolia) is the modern world reference for collector specimens.
- Often confused with calcite at first glance – but datolite has higher SG (2.96 vs 2.71).
Notable Varieties
- Botryolite (botryoidal habit)
The Chinese Angle
The Huanggang iron-tin skarn deposit in Inner Mongolia produces some of the world's finest datolite – pale yellow gemmy crystals up to 10 cm, often perched on bladed black ilvaite. Combination specimens are a Huanggang trademark.
Found at these Localities
- Boron / Death Valley Borate District (波伦/死亡谷硼酸盐矿)
- Huanggang Mine (黄岗梁铁锡矿)
- Inner Mongolia (内蒙古)
