Canadian Black

Submitted by Raven Mueller on Wed, 2014-07-09 08:27
Stone Type (Commercial): 
Physical Data
Munsell Color(s): 
Stone Type (Lithologic): 
Grain Size: 
Very Fine
Petrographic Description: 

Specimen: 2014-013

This specimen is a dark gray slate. The color of the specimen suggests the presence of significant graphite dust. Owning to the aphanitic nature of the material, many of the constituent minerals in this specimen cannot be identified through microscopy. Quartz/feldspar grains are common with a maximum dimension of .06 mm, most are smaller. Various species of mica presumably form the majority of the specimen’s fabric, but these are generally too small to be individually perceived. Identifiable crystals of mica are.1 mm and less in length and show some orientation preference. Carbonate minerals are abundant and occupy about 20 percent of slide area with a maximum crystal dimension of about .06 mm, the vast majority are under .02 mm. Carbonate crystals are a mix of anhedral and rhombohedral forms. Opaque minerals make up approximately 5 to 15 percent of slide area. Relict sedimentary features are faintly visible on macro-inspection of the slide. Under the microscope these patterns are perceptible only as slight differences in the translucency of the aphanitic component. Overall the lack of more significant grain elongation and orientation prevalence indicates very low grade metamorphism. This may be due to the slide’s orientation, which is perpendicular to the likely direction of maximum tectonic stress.
7/16/14 MP


Click thumbnail for larger image.
Specimen ID
2014-013 Image of specimen in dry conditions. Finish: Natural cleftdownload image Close-up image of specimen in dry conditions. Finish: Natural cleftdownload image

Thin Sections

Click thumbnail for larger image.
Specimen ID Non-polarized Cross-polarized
2014-013 Specimen shown in non-polarized image Specimen shown in cross-polarized image


No quarry information available for this stone.

Report an Issue

Type the words or phrase shown below to verify that you are not a robot.