Angelite
1 in the gallery
Angelite is a phosphate-free mineral variety of gypsum with a characteristic pale blue to blue-gray color. It typically forms in granular to acicular aggregates, often with a waxy to vitreous luster that highlights its delicate hue and translucent to semi-translucent appearance. Commonly found in sedimentary ore deposits and hydrothermal replacement environments, angelite crystals can occur as nodular masses or as well-formed, though not oversized, crystal associations. Notable specimens have come from Peru and Germany, among other localities, where the mineral forms within altered gypsum environments, occasionally linked to anhydrite replacement processes.
- Formula
- CaSO4
- Rarity
- Common
- Stability
- Moderately Stable
- Collector interest
- Moderate Interest
- Classification notes
- Sulfates (Calcium sulfate hydrate) – Gypsum group (Strunz 7.C)
Key characteristics
- Crystal system
- orthorhombic
- Mohs hardness
- 3–3.5
- Specific gravity
- 2.9–3
- Luster
- vitreous, pearly
- Transparency
- transparent, translucent
- Color
- blue, white, gray, violet
- Streak
- white
- Cleavage
- perfect
- Fracture
- uneven, splintery
- Crystal habit
- tabular, prismatic, fibrous, granular, massive
- Gem mineral
About Angelite
Collectors prize angelite for its distinctive color, gentle tones, and relatively clean surfaces that display light within the crystal framework. It is typically cut or kept in its natural form, where the soft blue can contrast with darker matrix minerals, enhancing its display value. Though not among the hardest minerals, angelite remains approachable for display cabinets and study pieces, offering an appealing example of how mineralogy can produce soothing color alongside classic gypsum habit.