Tincalconite
4 in the gallery
Tincalconite is a hydrated borate mineral with the formula Na2[(B4O7)·5H2O]. It commonly forms as acicular to tabular crystals and can present a pale to colorless appearance with a vitreous to glassy lustre. Habit often includes bladed or fibrous aggregates, and it may occur as compact crusts or crusty coatings on matrix rocks. Specimens are frequently associated with other borates and evaporite minerals, and they can be relatively soft, showing good cleavage in certain directions. While its crystal size can vary, the finest examples tend to display a delicate transparency and a snowy appearance that appeals to micromounters and cabinet collectors alike.
- Formula
- Na2(B4O7) · 5H2O
- Rarity
- Rare
- Stability
- Moderately Stable
- Collector interest
- Very High Interest
- Classification notes
- Borates; Hydrated borates, Strunz 6.B (borates with H2O)
Where Tincalconite is found
About Tincalconite
Notable specimens originate from the United States, where environments favorable to borate mineral deposition support its occurrence. Collectors value tincalconite for its rarity in a hydrated borate family and for the locale-specific character that stockpiles a sense of provenance. The mineral’s fragile, glassy look and light coloration make it a visual contrast against darker matrix material, enhancing display appeal. For many, tincalconite represents a window into evaporite geochemistry and the dynamic hydration states minerals can exhibit within arid to semi-arid settings.