Sauconite
A variety of Minerals
What is Sauconite?
Sauconite is a complex phyllosilicate mineral of the smectite clay group, formula Na0.3Zn3(SiAl)4O10(OH)2·4H2O. It forms soft earthy bluish white to red-brown monoclinic crystals typically massive to micaceous in habit. It has a Mohs hardness of 1 to 2 and a specific gravity of 2.45. Optically it is biaxial positive with refractive index values of nα = 1.550 - 1.580, nβ = 1.590 - 1.620 and nγ = 1.590 - 1.620. It is found in vugs and seams in the oxidized zones of zinc and copper deposits. It occurs in association with hemimorphite, smithsonite, chrysocolla, coronadite and various iron oxides. It was named for the Saucon Valley in Pennsylvania, where it was originally discovered in 1875.
Market Value Factors
Pricing varies for every rock and mineral, so use these universal factors to gauge Sauconite before comparing listings or appraisals.
Size & Weight
Larger, intact specimens usually command higher prices.
Rarity & Demand
Scarce material or popular varieties sell at a premium.
Condition & Finish
Chips, repairs, and heavy wear lower value; clean prep helps.
Treatment & Provenance
Untreated specimens with documented locality are prized.
Sauconite Localities Map
See where Sauconite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
Quick Facts
Physical Properties
- Color
- Reddish brown
- Hardness (Mohs)
- 1 - 2
Chemical Properties
- Chemical Formula
- Na0.3Zn3((Si,Al)4O10)(OH)2 · 4H2O
- Elements
- Al, H, Na, O, Si, Zn
Identify Sauconite Instantly
- Snap a photo, get instant results
- 6,700+ rocks, minerals & crystals
- Discover collecting spots near you
Sauconite FAQs
How do I identify Sauconite?
Sauconite can be identified by its hardness of 1 - 2 on the Mohs scale, Reddish brown color. Look for these key characteristics when examining specimens.
What color is Sauconite?
Sauconite typically appears in Reddish brown. Color can vary depending on impurities and formation conditions.
How hard is Sauconite?
Sauconite has a hardness of 1 - 2 on the Mohs scale. This makes it a soft mineral that can be scratched easily.
%252FAbenakiite-(ce)-01.jpg&size=small)
