Fluorapophyllite

Object/Artifact

-

Crater Rock Museum

Name/Title

Fluorapophyllite

Entry/Object ID

2004.1.44

Description

Assemblage Zone: pegmatite dikes Chemical Composition: (K,Na)Ca4Si8O20(F,OH) - 8 Crystal System: Tetragonal System Description: Common Name: Apophyllite Group Name: Apophyllite Chemistry: (K,Na)Ca4Si8O20(F,OH) - 8H2OColor is clear, white, green, yellow, pink, violet or rarely brown. Location: Rahuri, Maharashtra, India Description: Small green squared crystals. PHYSICAL CHARACTERISTICS 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.n. Best Field Indicators are crystal habit, striations, associations, environment of formation, cleavage and luster on cleavage surfaces. Fracture: uneven Hardness: 5 Apatite 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. Notable Occurrences are extensive and include the Deccan Traps (ancient basalt flows) in India especially around Poona, also found in Christmas Mine, Arizona; Fairfax, Virginia; Upper Peninsula, Michigan; Oregon; Pennsylvania; Paterson, New Jersey and North Carolina, USA; Rio Grande do Sul, Brazil; Isle of Skye, Scotland; Collinward, Northern Ireland; Mexico; Nova Scotia and Mont Saint-Hilaire, Canada; Iceland; Kongsberg, Norway; Harz Mountains, Germany and Sampo Mine, Takahashi, Okayama, Honshu, Japa Specific Gravity: 2.3-2.4 Streak: White Variety: FLUORAPOPHYLLITE (K, Na)Ca4Si8O20(F,OH) - 8H2O Tetragonal; 4/m 2/m 2/m White, colorless, green, yellow or violet Not named Some specimens fluoresce pale green or yellow HYDROXYAPOPHYLLITE KCa4Si8O20(OH, F) - 8H2O Tetragonal; 4/m 2/m 2/m White or colorless Ore Knob Mine, Jefferson, North Carolina Non-fluorescent NATRO-APOPHYLLITE NaCa4 Si8O20F - 8H2O Orthorhombic; 2/m 2/m 2/m (pseudotetragonal) brown, brownish yellow, yellow or colorless Sampo Mine, Takahashi, Okayama, Honshu, Japan Non-fluorescent

Collection

Suomynona Mineral Collection, Suomynona Collection

Acquisition

Accession

2004.1

Source or Donor

Suomynona Mineral Collection

Acquisition Method

Donation

Dimensions

Width

2-1/4 in

Length

3-1/2 in

Weight

0.9 oz

Dimension Notes

Dimension taken at widest points

Location

Location

Display Case

FS-16

Room

Frieda Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Curtis Gardner

Date

May 25, 2023

Notes

Added current location

Location

Container

center

Drawer

bottom tier

Shelf

east side, east side

Wall

SE of center

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Scott Longan

Date

August 25, 2009

Location

Container

Right

Cabinet

Case#39

Wall

West

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent