Submitted by Raven Mueller on Tue, 2014-07-08 08:32
Stone Type (Commercial): 
Physical Data
Munsell Color(s): 
Absorption (%): 
Flexural Strength, Dry (psi): 
Modulus of Rupture, Dry (psi): 
Compressive Strength, Dry (psi): 
Abrasion Resistance: 
Stone Type (Lithologic): 
Grain Shape: 
Grain Size: 
Petrographic Description: 

Specimen: 2013-005

This sample is a plutonic rock dominated by mostly anhedral feldspar and a lesser amount of quartz. The crystalline structure is generally coarse. Some predominantly quartz sections near aplitic textures. The quartz in these zones present predominantly wave extinction and have a macrostructure that suggests minimal foliation. Maximum crystal dimension in the sample is 12 mm (feldspar) and minimum is .1 mm (quartz). Quartz grains are notably smaller on average than feldspar grains. Modal grain size is around 3 to 4 mm for feldspar and .5 to .75 mm for quartz. Feldspar twinning patterns include tartan (microcline) and albite. Grain boundaries are mostly consertal sutured. Intergrowth textures include abundant microperthitic examples involving multiple species of feldspar and rare granophyric with plagioclase intergrown with quartz. Accessory minerals include biotite, which is common at about 5 to 10 percent of slide area. Muscovite is also relatively ubiquitous occurring as very small inclusions in feldspars and as larger foliated masses. Muscovite still constitutes only 1 to 2 percent of slide area at most. Opaques are relatively rare and comprise less than 5 percent of slide area. The only other noted mineral is a localized occurrence of what is likely arfvedsonite based on pleochroism and birefringence. Most secondary minerals occur in bands associated with the predominantly aplitic quartz. There are slight signs of insipient weathering of feldspars with many grains presenting a dusty look. What is likely sericite is present in small patches (~10 µm) on some feldspar grains, but these cannot be definitively discerned from other micas such as muscovite also present as inclusions in feldspars. Rarely, grain boundaries and cracks in grains have begun to fill with brownish clay material (>20 µm in width).
7/8/2015 MP


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Specimen ID
2013-005 Image of specimen in dry conditions. Finish: Polisheddownload image

Thin Sections

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Specimen ID Non-polarized Cross-polarized
2013-005 Specimen shown in non-polarized image Specimen shown in cross-polarized image


NOTE: Quarry locations are approximate.

Bellingham Quarry
US Route 75
56276 Odessa , Minnesota
United States
45° 11' 58.9344" N, 96° 17' 19.572" W
Minnesota US

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