Mineralpedia Details for Armstrongite

Formula

CaZrSi₆O₁₅·2.5H₂O 

Crystal System

Monoclinic 

Crystal Habit

Bladed, Spherical, Aggregates 

Cleavage

Perfect, Distinct, None 

Luster

Vitreous (Glassy) 

Color

light brown, reddish brown 

Streak

brownish white 

Class

Monoclinic - Sphenoidal 

Fracture

Brittle 

Hardness

4.5 

WebMineral

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Mindat

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Special Info

Type Locality

Reddish brown fine grain crystalline areas with Aegerine or Arfvedsonite. Armstrongite is named after Neil Armstrong, the first man on the moon. It was named on the 10th anniversery of the Moon landing.