Tugtupite,Analcime

Object/Artifact

-

Crater Rock Museum

Tugtupite,Analcime

Tugtupite,Analcime

Name/Title

Tugtupite,Analcime

Entry/Object ID

2014.1.100

Description

Formula: Na4BeAlSi4O12Cl Colour: Commonly red, also white to pink, bluish white, greenish white Lustre: Sub-Vitreous, Waxy, Greasy, Dull Hardness: 4 Specific Gravity: 2.33 Crystal System: Tetragonal Member of: Helvine Group Name: Named after its discovery locality, Tugtup Agtâkorfia, Narsaq municipality, Greenland. Type Locality: Tugtup Agtakôrfia, Tunulliarfik Fjord, Ilímaussaq complex, Kujalleq, Greenland Chemical Composition: Na4BeAlSi4O12Cl Crystal System: Hexagonal System Description: Common Name: Tugtupite,Analcime Chemistry: Na4BeAlSi4O12Cl Class: Location: Tasaq Slope,Ilimaussaq Complex, Greenland Description: Pink Tugtupite in a matrix of translucent Analcime with small patches and streaks of a gray mineral. It is Florescent. PHYSICAL CHARACTERISTICS: Help on Cleavage: Cleavage: {111} Imperfect Help on Color: Color: White, Pink, Crimson, Blue, Green. Help on Density: Density: 2.36 Help on Diaphaneity: Diaphaneity: Transparent to Translucent Help on Fracture: Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern. Help on Habit: Habit: Massive - Uniformly indistinguishable crystals forming large masses. Help on Hardness: Hardness: 4 - Fluorite Help on Luminescence: Luminescence: Fluorescent and tenebrescent, Short UV=dark crimson, Long UV=deep rich orange light crimson. Help on Luster: Luster: Vitreous - Greasy Help on Streak: Streak: white Fracture: Conchoidal Hardness: 4 Fluorite Luster: Vitreous Occurrence: Named for its type locality at Tugtupt agtakorfia, Greenland, Tugtupite can be found in only three countries: Russia, Greenland, and Canada. It occurs as a replacement for chkalovite in hydrothermal veins that cut sodalite and syenite and also as an alteration mineral in pegmatites in alkalic massifs. Tugtupite is piezoelectric, meaning it can accumulate a charge in response to pressure. Fluorescent and phosphorescent a red to pink color under ultraviolet light. Tugtupite is also photochromic, pale colors will reversibly change to pink upon exposure to light or X-rays. Rock Type: Igneous Specific Gravity: 2.36 Streak: White Variety: THE MINERAL ANALCIME •Chemistry: NaAlSi2O6-H2O, Hydrated Sodium Aluminum Silicate •Class: Silicates •Subclass: Tectosilicates •Group: Zeolites •Uses: mineral specimen and chemical filter. •Specimens Analcime is a popular and interesting mineral. It is sometimes known as analcite, although analcime is preferred. It is one of the few minerals that characteristically forms its own unique crystal. Well, not quite its own unique crystal, but pretty close. It forms the isometric trapezohedron. The minerals of the garnet group and high temperature leucite are the only common minerals that will also form the trapezohedron. The trapezohedron has 24 deltoid-shaped faces, where each face occupies one third of the position of a single octahedron's face. Distinguishing analcime from the garnets and leucite is relatively easy in some cases. The garnets are much harder and usually deeply colored. Leucite has a much lower density and usually has a dull luster. Also leucite is typically embedded in host rock where as analcime, when displaying good crystals and not massive or granular, is loose or attacted to other minerals in volcanic cavities. Analcime, AlSi2O6-H2O is actually distantly related to leucite, KAlSi2O6. Leucite is a member of the feldspathoid group of minerals. Minerals whose chemistries are close to that of the alkali feldspars but are poor in silica (SiO2) content, are called feldspathoids. Feldspathoids are commonly found in silica-poor igneous rocks, where analcime is sometimes present as well. Analcime is sometimes placed in the feldspathoid group since its chemistry and occassional occurrences are similar. Analcime's structure however has a typical zeolite openness about it that allows large ions and molecules to reside and actually move around inside the overall framework. The structure contains large open channels that allow water and large ions to travel into and out of the crystal structure. The size of these channels controls the size of the molecules or ions, and therefore a zeolite like analcime can act as a chemical sieve. PHYSICAL CHARACTERISTICS: • Color is clear, white or gray, with greenish, yellowish and reddish tints possible. • Luster is vitreous. • Transparency: crystals are transparent to translucent. • Crystal System is isometric; 4/m bar 3 2/m • Crystal Habits include the characteristic trapezohedron as well as the rare cube modified by trapezohedral faces. Also granular and massive. • Cleavage is absent. • Fracture is uneven. • Hardness is 5 - 5.5. • Specific Gravity is approximately 3.2 (average) • Streak is white. • Associated Minerals are quartz, calcite, serandite, apophyllite, natrolite, stilbite, heulandite and other zeolites. • Notable Occurrences include Mont St. Hilaire, Quebec; Iceland; several localities in Oregon, Colorado and New Jersey, USA; Nova Scotia and Switzerland. • Best Field Indicators are crystal habit, density, low hardness, luster and associations.

Collection

RAGM Mineral Collection

Acquisition

Accession

2014.1

Source or Donor

Crater Rock Museum (unknown donors)

Acquisition Method

Gift

Dimensions

Width

6 in

Depth

4-1/2 in

Length

7-1/2 in

Location

Location

Shelf

CS-F-4

Room

Curation Storage

Building

Crater Rock Museum

Category

Storage

Moved By

Curator

Date

February 16, 2024