Fairy cross
Variety Fe2Al9Si4O23(OH)
Also called Fairy stone and Staurolite cross
About it
Staurolite twinned into a cross at 90° or 60°, weathered out of schist. Fairy Stone State Park in Virginia and Fannin County, Georgia, are well known; many crosses sold to tourists are carved or moulded fakes.
- Type
- Variety
- Group
- Staurolite variety
- Formula
- Fe2Al9Si4O23(OH)
- Hardness (Mohs)
- 7–7.5
- Specific gravity
- 3.74–3.83
- Streak
- white to greyish
- Lustre
- vitreous (glassy), resinous, dull
- Crystal system
- Monoclinic
- Colours
- brown, reddish brown, black
- Transparency
- opaque, translucent
- Cleavage and fracture
- distinct in one direction; uneven to subconchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.