Iron flowers aragonite

General

Chemical formula: CaCO3

Strunz classification: 05.AB.15

Crystal symmetry: Orthorhombic (2/m 2/m 2/m) - dipyramidal

Unit cell: a = 4.95 Å, b = 7.96 Å, c = 5.74 Å; Z = 4

Identification

Color: White, red, yellow, orange, green, purple, grey, blue and brown

Crystal habit: Pseudohexagonal, prismatic crystals, acicular, columnar, globular, reniform, pisolitic, coralloidal, stalactitic, internally banded

Crystal system: Orthorhombic

Twinning: Polysynthetic parallel to {100} cyclically on {110}

Cleavage: Distinct on {010}, imperfect {110} and {011}

Fracture: Subconchoidal

Tenacity: Brittle

Mohs scale hardness: 3.5-4

Luster: Vitreous, resinous on fracture surfaces

Streak: White

Diaphaneity: Translucent to transparent

Specific gravity: 2.95

Optical properties: Biaxial (-)

Refractive index: nα = 1.529 - 1.530 nβ = 1.680 - 1.682 nγ = 1.685 - 1.686

Birefringence: δ = 0.156

2V angle: 18°

Solubility: Dilute acid

Other characteristics: Fluorescence: pale rose, yellow, white or bluish; phosphorescence: greenish or white (LW UV); yellowish (SW UV)


Flickr page for this photo.

Visit the Eye for Science Flickr group.

Get the "Eye for Science" widget here and install it on your own blog. Spread the scienticity!

Like this image? Want it for your smartphone wallpaper?
Use this QR Code to load it on your smartphone and enjoy!