Stibiconite

Object/Artifact

-

Crater Rock Museum

Stibiconite

Stibiconite

Name/Title

Stibiconite

Entry/Object ID

2009.62.25

Description

Chemical Composition: Sb3O6(OH). Crystal System: Cubic or Isometric S Description: Common Name: Stibiconite Chemistry: Sb3O6(OH) , Antimony Oxide Hydroxide. Group: Oxides Location: Xikuaxian Mine, Hunan Province, China Description: Light almost green like colored with some white crystals. The crystal structure resembles straw or sticks that are perfectly straight cut coming up from the bottom. PHYSICAL CHARACTERISTICS: Color is white or gray but usually tinted brown or yellow. Luster is earthy. Transparency crystals are opaque. Crystal System is isometric, possibly. Crystal Habits: include the earthy masses and crust but well known for its stibnite pseudomorphs showing a sword-like bladed habit, singular or in radiating clusters. Cleavage none Fracture is earthy Hardness is 4 - 5.5 Specific Gravity is 3.5 - 5.9 (above average to heavy) Streak is white. Associated Minerals include stibnite, valentinite, and other antimony oxides. Other Characteristics: a white coating may appear on specimens with time (don't try to remove). Best Field Indicators are stibnite-like crystals, color, luster, hardness and density. Fracture: Clay Like Hardness: 5 Apatite Luster: Vitreous Occurrence: Stibiconite forms in the oxidation zone of antimony sulfides. The oxygens oxidize a portion of the antimonies (Sb) from +3 (as in stibnite) to +5. The two different valences occupy different sites in the structure of the mineral, since the size of the atoms diminsh greatly when reduced in charge. To represent this, the formula could be written as so, Sb(+3)Sb(+5)2O6(OH). This formula more closely fits the general formula for the Stibiconite Group, M1 - 2X2O6(O, OH, F). Rock Type: Sedimentary Specific Gravity: 3.5-5.9 Streak: White Texture: Microcrystaline Variety: Stibiconite is a rather rare mineral, but is known among collectors for its first class pseudomorphs. A pseudomorph is an atom by atom replacement of one mineral's chemistry to form another completely different mineral. The process leaves the crystal shape of the lost mineral intact. Pseudomorph means false (pseudo) shape (morph). In the case of stibiconite, the mineral that is lost is stibnite, Sb2S3. Stibnite's sword-like crystals arranged in radiating clusters are truly works of natural art. A pseudomorph of stibiconite can perfectly match the sword-like shape of stibnite's crystals. It can do this because the process is done slowly, allowing the oxygens to replace the sulfurs essentially one atom at a time. However, stibiconite lacks the metallic luster or steel gray color of stibnite. If two classic specimens of the minerals are put side by side the color and luster contrasts along with the similarity of the crystal shapes would simply fasinate the onlooker.

Collection

RAGM Mineral Collection

Acquisition

Accession

2009.62

Source or Donor

Museum Collection of Minerals

Acquisition Method

Donation

Dimensions

Width

3 in

Depth

3 in

Length

3-1/2 in

Weight

1.65 oz

Dimension Notes

Dimension taken at widest points

Location

Location

Display Case

FS-3-B

Room

Frieda Smith Hall

Building

Crater Rock Museum

Category

Exhibit

Moved By

Jillian Mather Kettley

Date

January 29, 2025

Notes

Location/ inventory