Editorial Feature

Wardite - Occurrence, Properties, and Distribution

Jun 3 2014

Wardite is a hydrous sodium aluminum phosphate hydroxide mineral, and it crystallizes in the tetragonal trapezohedral class.

It was named after Henry Augustus Ward, an American collector and dealer in natural history objects from Rochester in New York, USA.

Properties of Wardite

The following are the key properties of Wardite:

Cell Data
- Space Group: P4₁2₁2 or P4₃2₁2
- a = 7.03(1)
- c = 19.04(1)
- Z = 4

Crystal Data
- Tetragonal
- Point Group: 422
- Dipyramidal pseudo-octahedral crystals, with {010}, {011}, {012}, {100}, rarely {001}, typically striated ⊥ [001], to 4cm
- X-ray powder pattern: 4.74 (10), 2.994 (7), 2.591 (7), 3.085 (6), 1.516 (5), 2.825 (4), 2.108 (4)

Chemical Composition

Elements	Content 1	Content 2
Al₂O₃	38.70	38.43
P₂O₅	35.12	35.67
H₂O	17.88	18.11
Na₂O	7.51	7.79
FeO	0.26
MgO	0.21
K₂O	0.16
Total	99.84	100.00

Optical Properties
- Transparent to opaque
- Color: White, colorless, pale green, blue-green, yellow-green, pale yellow, brown; colorless in transmitted light
- Luster: Vitreous
- Optical Class: Uniaxial (+)
- ω = 1.586–1.594
- ε = 1.595–1.604

Estimated Properties

Electron density	Bulk density (electron density) = 2.79 g/cm³ note: Specific gravity of Wardite = 2.78 g/cm³
Photoelectric	PE_Wardite = 1.47 barns/electron U = PE_Wardite x ρElectron density = 4.10 barns/cm³
Fermion index	Fermion index = 0.00027 Boson index = 0.99972
Radioactivity	Wardite is not radioactive

How to Identify Wardite

Wardite varies from vitreous green, bluish-green, white to colorless crystal masses. It has a transparent to translucent appearance, and forms fibrous encrustations. Its radial crystals radiate from the center without producing stellar forms. It has a perfect cleavage with white streak, non-magnetic, and non-fluorescent properties.

It has a relative hardness of 5, and an average density of 2.84 g/cm³.

Global Distribution

Wardite is distributed in the following places:

Little Green Monster mine, Clay Canyon, USA
Dunton quarry and the Bell Pit, Newry
Palermo #1 mine, North Groton
Grafton Co. New Hampshire
Hugo pegmatite, near Keystone
Tip Top mine, 8.5km south-west of Custer, Custer Co. South Dakota
Big Fish River–Rapid Creek area, Yukon Territory, Canada
Lavra da Ilha pegmatite, in the Jequitinhonha River, Brazil
Pirineus mine, Itinga, Minas Gerais
Alto Patrimonio, Piedras Lavradas, Para´iba
Songo, Sierra Leone
Wolfsberg quarry, near Spittal, Carinthia, Austria
Ruffiac, Morbihan, and Montebras, Creuse, France
Iron Monarch quarry, Iron Knob, South Australia
Milgun Station, Western Australia

Occurrence of Wardite and Useful Mineral Association

Wardite occurs as a component of low-temperature phosphatic nodules, and is an uncommon species in complex zoned pegmatites.

It is commonly associated with siderite roscherite (pegmatites), eosphorite, hydroxyl-herderite, fairfieldite, montgomeryite, whitlockite, mitridatite, ferrisicklerite, crandallite, millisite, and variscite.