Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
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Actinolite from
Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA


07474540017366282424057.jpg
Actinolite, etc.

Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA
07474540017366282424057.jpg
Actinolite, etc.

Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA
07325670017366282438828.jpg
Actinolite, etc.

Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA
Locality type:Quarry
Classification
Species:Actinolite
Formula:◻Ca2(Mg4.5-2.5Fe0.5-2.5)Si8O22(OH)2
Comments:ACTINOLITE.
ALBITE. (Reported by J. Griesbach, 1975).
ANTHOPHYLLITE. Creamy gray veinlets in serpentinite float.
ANTIGORITE. (G. T. Faust, 1967). Constitutes bulk of serpentinite as interlocking microscopic laths and plates or as tough, brittle, dark
Confirmation
Validity:Believed Valid
Associated Minerals Based on Photo Data:
Quartz1
Data
Mineral Data:Click here to view Actinolite data
Locality Data:Click here to view Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA
Data Identifiers
Mindat Occurrence Record ID:36807
Long-form Identifier:1:3:36807:4
GUID (UUID V4):0
Nearest other occurrences of Actinolite
20.7km (12.8 miles) ⓘSoapstone Valley, NW Washington, District of Columbia (Washington D.C.), USA
25.0km (15.6 miles) ⓘNew Goose Creek Quarry, Leesburg, Loudoun County, Virginia, USA
26.4km (16.4 miles) ⓘHighway 50 intersection, Centreville, Culpeper Basin, Fairfax County, Virginia, USA
28.0km (17.4 miles) ⓘPotomac Mine, Leesburg, Loudoun County, Virginia, USA
34.1km (21.2 miles) ⓘSavage Gabbro Quarry, Savage, Howard County, Maryland, USA
35.9km (22.3 miles) ⓘVeasco Quarry (MRDS - 10276445), Oatlands, Loudoun County, Virginia, USA
36.3km (22.5 miles) ⓘFairfax Quarry, Centreville, Culpeper Basin, Fairfax County, Virginia, USA
38.4km (23.8 miles) ⓘNew London Mine (Linganore Mine), New London, Frederick County, Maryland, USA
39.1km (24.3 miles) ⓘCarroll Mine, Sykesville, Carroll County, Maryland, USA
39.8km (24.7 miles) ⓘLoudon Marble Company Quarry, Loudoun County, Virginia, USA
References
Jack Nelson, Compiler from two references and personal communications, May 2000 (See descriptive notes for quarry for reference citations)>
 
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