Scolecite/Fluorapophyllite

Object/Artifact

-

Crater Rock Museum

Name/Title

Scolecite/Fluorapophyllite

Entry/Object ID

2009.62.66

Description

Chemical Composition: see description Crystal System: Tetragonal System Description: Common: Apophyllite / Scolecite : Chemistry: (K,Na)Ca4Si8O20(F,OH) - 8H2O, Hydrated Potassium Calcium Sodium Silicate Fluoride Hydroxide / CaAl2Si3O10-3H2O, Hydrated calcium aluminum silicate Group: Zeolites Location: Jalgaon, India Description: Large cluster of hairlike crystals, white to light pink with a cluster of light green crystals intertwinned at the base. THE PHYSICAL CHARACTERISTICS OF APOPHYLLITE: Color is clear, white, green, yellow, pink, violet or rarely brown. Luster is vitreous to pearly on cleavage surfaces. Transparency: Crystals are transparent to translucent. Crystal System is tetragonal; 4/m 2/m 2/m; natroapophyllite is orthorhombic, 2/m 2/m 2/m. Crystal Habits include four sided prisms (with a square cross-section) truncated with either a steep four sided pyramid or a pinacoid termination or both. If the pyramids are missing, the crystals can look cubic. Rarely are the prisms missing, but if they are, crystals could appear octahedral because of the four sided pyramids. The faces of the pyramids do not lineup with the prism faces but with their edges, therefore the pyramid faces have four edges and appear diamond shaped instead of triangular like the pyramid faces of quartz. Rare tabular hydroxyapophyllite crystals are also known. Cleavage is perfect in one direction (basal). Fracture is uneven. Hardness is 4.5 - 5. Specific Gravity is approximately 2.3 - 2.4 (lighter than most translucent minerals). Streak is white. Other Characteristics: Prism faces are striated lengthwise, some specimens are fluorescent and crystals will flake when heated. Associated Minerals are prehnite, quartz, heulandite, stilbite, natrolite, analcime, datolite, babingtonite, cavansite, calcite, idocrase, wollastonite, kinoite, gyrolite and many other zeolites. Best Field Indicators are crystal habit, striations, associations, environment of formation, cleavage and luster on cleavage surfaces. PHYSICAL CHARACTERISTICS OF SCOLECITE Color is clear or white. Luster is vitreous to silky. Transparency: crystals are transparent to translucent. Crystal System is monoclinic; 2/m Crystal Habits include sprays of thin acicular crystals with slanted terminations. Also occurs in radiating fibrous clusters. Cleavage is perfect in two directions, prismatic. Cleavage is hard to see due to small crystal size. Fracture is conchoidal. Hardness is 5. Specific Gravity is approximately 2.2 (very light) Streak is white. Associated Minerals are quartz, apophyllite, babingtonite, heulandite, stilbite and other zeolites. Best Field Indicators are crystal habit, hardness, density and associations. Fracture: conchoidal Hardness: 4 Flourite Luster: Vitreous Occurrence: Apophyllite specimens are found in ancient lava and basalt flows. The crystals grow in the now solid cavities, called amygdules or vesicles, formed by air bubbles when the rock was molten. Apophyllite is also found in the voids in the contact metamorphic zone limestones that surround intrusive rocks. Scolecite also from in much the same setting as apophyllite and other zeolites. Rock Type: Sedimentary Specific Gravity: 2.3-2.4 Streak: white Variety: The name apophyllite is derived from the Greek apophylliso, meaning "it flakes off," a reference to this class's tendency flake apart when heated, due to water loss and refers to a specific group of phyllosilicates, a class of minerals that also includes the micas. Scolecite, a calcium zeolite, natrolite, a sodium zeolite, and mesolite, a calcium and sodium zeolite, are closely related and sometimes found together.

Collection

RAGM Mineral Collection

Acquisition

Accession

2009.62

Source or Donor

Museum Collection of Minerals

Acquisition Method

Donation

Dimensions

Width

6-1/2 in

Depth

3-1/2 in

Length

5 in

Weight

3.86 oz

Dimension Notes

Dimension taken at widest points

Location

Location

Display Case

DS-6

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Curtis Gardner

Date

May 24, 2023

Notes

Added current location

Location

Container

Center

Drawer

3rd Shelf

Shelf

Center, Center

Wall

South wall

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Steve Miller

Date

January 14, 2010

Location

Drawer

2nd from right

Shelf

middle 3rd shelf, middle 3rd shelf

Wall

South wall

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Scott Longan

Date

September 25, 2009

Location

Wall

south wall

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Josh E.

Date

September 19, 2009

Location

Container

Center

Drawer

Top Shelf

Shelf

Center

Cabinet

Case #41

Wall

South wall

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent