Hanksite

Object/Artifact

-

Crater Rock Museum

Name/Title

Hanksite

Entry/Object ID

2009.62.80

Description

Chemical Composition: Na22K(SO4)9(CO3)2Cl Crystal System: Hexagonal System Description: Common Name: Hanksite Chemistry: Na22K(SO4)9(CO3)2Cl, Sodium Potassium Sulfate Carbonate Chloride Group: Sulfates / Carbonate Location: San Bernardino, CA Description: Dull appearance with a pale green color. Crystals are smoothed over on the edges and are clumped tightly together on a small white and tan crystalline matrix. PHYSICAL CHARACTERISTICS: Color is colorless, white, gray, green or yellow; rarely black. Luster is vitreous Transparency: Crystals are transparent to translucent. Crystal System is hexagonal; 6/m 2/m 2/m. Crystal Habits include the typical hexagonal dipyramid terminating an hexagonal prism. The pyramids are often truncated by pinacoids. The six faces of the pyramids are aligned with the six faces of the prism. Tabular and twinned crystals are also common. Cleavage is perfect in one direction. Fracture is uneven. Hardness is 3 - 3.5 Specific Gravity is approximately 2.5 (slightly below average). Streak is white. Other Characteristics: Has a salty taste, a white powdery film will often cloud crystals and some specimens are fluorescent yellowish-white under longwave ultraviolet light. Associated Minerals are halite, borax, trona, nahcolite, tincalconite and other evaporite minerals. Best Field Indicators include crystal habit, taste, occurrences and associations. Fracture: conchoidal Hardness: 3 Calcite Luster: Vitreous Occurrence: Hanksite forms very nice crystals in evaporite deposits. These evaporite deposits occur in arid environments. Water, carrying dissolved minerals, floods into a dry lake beds and then just sits. The arid conditions evaporate the water and concentrate the ions. When the water is almost gone, crystals start to form. The mineral halite (salt) is one of the first minerals to crystallize. As the water becomes even more concentrated, eventually rare and unusual minerals such as borax or hanksite will crystallize too. Hanksite crystals can be large and well formed, but are not very complex. Rock Type: Sedimentary Specific Gravity: 2.5 Streak: white Variety: Hanksite is a mineral, distinguished as one of only a handful that contain both carbonate and sulfate ion groups. This can bring confusion as to which category to place it into, normally it is regarded as sulfate class mineral as there are more of these groups than the carbonate.

Collection

RAGM Mineral Collection

Acquisition

Accession

2009.62

Source or Donor

Museum Collection of Minerals

Acquisition Method

Donation

Dimensions

Height

3 in

Width

2-3/4 in

Length

5-1/4 in

Weight

1.91 oz

Dimension Notes

Dimension taken at widest points

Location

Location

* Untyped Location

DS-11

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Exhibit

Moved By

Ian C.

Date

January 21, 2025

Notes

USA Case Installation

Location

Display Case

FS-6-A

Room

Frieda Smith Hall

Building

Crater Rock Museum

Date

January 3, 2024