Name/Title
ScoleciteEntry/Object ID
78.63.387Description
Chemical Composition: (Na,Ca,K)4-9Al9Si27O72-n(
Crystal System: Monoclinic System
Description: Common Name: Zeolite(Stilbite)
Group Name:Silicates
Location: Maine
Chemistry: ( Na,Ca,K )4-9Al9Si27O2-n(H2O)
Description: Zeolite crystals and lava. Triangular or sheath shaped piece that is dark and light grey on greyish lava.
PHYSICAL CHARACTERISTICS:
Stilbite-Ca: NaCa4Al9Si27O72 · 28(H2O)
Stilbite-Na: Na9Al9Si27O72 · 28(H2O)
Composition Hydrous calcium sodium aluminum silicate, occasionally with some potassium. The ratio of calcium to sodium is variable. Variable Formula (Na,Ca,K)4-9Al9Si27O72 · n(H2O) Color White, beige, peach, pink, orange, light yellow, brown. Less commonly gray, red, or green. Streak Colorless Hardness 3.5 - 4 Crystal System Monoclinic
3D Crystal Atlas
(Click for animated model)
Single Pyramidal Stilbite Crystal
Tabular Widened Crystal
Crystal Forms
and Aggregates Single crystals are tabular and flattened, and usually with pointed termination. However, single individual crystals are very uncommon; crystals will usually be in platy aggregates, or more often in distinct curved aggregates of fan-shaped or wheat sheaf bundles, and in unique "bow tie" formations. Also radiating, globular, in bladed groups, as rounded balls of radiating crystals, and fibrous. Crystals are often doubly terminated, and aggregates may be twinned in interesting bisecting habits.
Transparency Transparent to translucent Specific Gravity 2.1 - 2.2 Luster Vitreous, pearly, dull Cleavage 1,1 Fracture Uneven Tenacity Brittle Other ID Marks Occasionally fluorescent yellow in UV light.
In Group Silicates; Tectosilicates; Zeolite Group Striking Features Crystal aggregate formations and association with other zeolites. Environment Most often in volcanic basalt and diabase. Also in altered metamorphic gneiss, and occasionally in granite pegmatites.
Rock Type Igneous, Metamorphic Popularity (1-4) 2 - See more at: http://www.minerals.net/mineral/stilbite.aspx#sthash.PsoZOipL.dpuf
Fracture: uneven
Hardness: 4 Fluorite
Luster: Vitreous
Occurrence: Stilbite is a common mineral and found worldwide. Only the most significant deposits will be mentioned here. The largest and most significant finds of Stilbite are from India, in the state of Maharshtra. Several localities there have produced outstanding examples of this mineral, with the cities such as Pune (Poona), Jalgaon, Nasik, Aurangabad, Mumbai, and Ahmadnagar being the most significant.
Iceland is a classic producer of Stilbite, and the locality of Teigarhorn, in Berufjördur, is especially noteworthy. The Faroe Islands (Denmark), which are composed of volcanic basalt, are also an important and classic locality. In Sweden, excellent brownish-yellow Stilbite crystal plates come from Malmberget, Lappland.
In the U.S., New Jersey is the most prolific producer of Stilbite, with many localities producing outstanding examples of this mineral. Foremost in importance are Paterson and Prospect Park, Passaic Co., producers of large and well-formed bow-ties and wheat sheaves. Highly lustrous white and cream Stilbite has come from the Braen Quarry, Haledon, Passaic Co., especially in white, rounded balls; and orange to brown crystal plates from Montclair/Little Falls, Essex/Passaic Cos. Exceptional bright orange Stilbite comes from the diabase at the Moore's Station Quarry, near Lambertville; and dense, lighter colored plates once came from Laurel Hill (Snake Hill), Secaucus, Hudson Co. Tan colored crystals came from the Millington Quarry, Somerset Co.; and yellow and orange radial aggregates from the Fanwood Quarry, Somerset Co.
Connecticut has produced fine Stilbite crystals at the O&G Quarry, Woodbury, Litchfield Co.; and the prolific locality of the Thomaston Dam railroad cut, Litchfield Co. was once a good producer. Other notable U.S. occurrences include the Fairfax quarry, Centreville, Fairfax Co., Virginia; Mill Creek, Polk Co., Oregon; the Skookumchuck Dam, Bucoda, Thurston Co., Washington; and Kalama and Signal Peak, Cowlitz Co., Washington.
In Canada, good crystals come from several localities in Nova Scotia near the Bay of Fundy, such as Cape D'or, Horshoe Cove, Wasson's Bluff, and Partridge Island.
Stilbite-Na is not commonly identified. Its type locality is Cape Pula, Cagliari, on the island of Sardinia, Italy.
- See more at: http://www.minerals.net/mineral/stilbite.aspx#sthash.PsoZOipL.dpuf
Rock Type: Igneous
Specific Gravity: 2. 1-2.2
Streak: ColorlessCollection
Delmar Smith Mineral CollectionDimensions
Height
3 inWidth
4-1/2 inDepth
1/2 inLength
2-1/2 inDimension Notes
Dimension taken at widest pointsLocation
Location
Shelf
CS-E-3Room
Curation StorageBuilding
Crater Rock MuseumCategory
StorageMoved By
Jillian Mather KettleyDate
March 5, 2024