Lecontite
A sodium-ammonium sulfate found in bat-guano caves — first collected in Honduras's Las Piedras Cave by John LeConte.
Intro adapted from Wikipedia (CC BY-SA).
Lecontite is an IMA-recognized mineral species in the sulfate class, with the chemical formula (NH₄)Na(SO₄)·2H₂O.
It crystallizes in the orthorhombic crystal system (space group P2_12_12_1).
Key properties: Mohs hardness 2–2.5; specific gravity 1.745; Vitreous luster; optically biaxial.
IMA symbol Lcn, grandfathered status — known before the IMA’s founding, named in 1858.
An early product of the breakdown of bat guano.
It is found associated with Thénardite, mascagnite, probable.
The mineral was named to honor John Lawrence LeConte (1825–1883), American entomologist, University of California, Berkeley, California, USA, who discovered the mineral.