File:Graphic granite (Ruggles Pegmatite, Devonian; Ruggles Mine, New Hampshire, USA) (48751570932).jpg
Original file (2,487 × 1,979 pixels, file size: 3.18 MB, MIME type: image/jpeg)
Captions
Summary
[edit]DescriptionGraphic granite (Ruggles Pegmatite, Devonian; Ruggles Mine, New Hampshire, USA) (48751570932).jpg |
Graphic granite from a pegmatite body in the Devonian of New Hampshire. (8.1 centimeters across at its widest) Dark gray = quartz (SiO2 - silica) Whitish = K-feldspar (KAlSi3O8 - potassium aluminosilicate) Graphic granite (a.k.a. runic granite; a.k.a. runite) has an odd but distinctive type of crystalline texture. Graphic granites are typically bimineralic and consist of interpenetrating crystals (quartz in potassium feldspar), in a way that somewhat resembles ancient cuneiform writing (“graphic”). Some observed examples resemble Arabic writing. These rocks occur in pegmatitic granite intrusions. This example is from the Ruggles Pegmatite Mine near Grafton, New Hampshire. The Ruggles Mine started off in the early 1800s as a muscovite mica mine, but it's now a tourist site and mineral collecting locality. Its walls have beautiful exposures of a mid-Paleozoic granite pegmatite, having unbelievably large crystals. Well over 100 minerals have been reported from this pegmatite, but the most common rock-forming minerals here are quartz, potassium feldspar, biotite mica, muscovite mica, and schorl tourmaline. The Devonian-aged pegmatite at Ruggles Mine is one of several in the Grafton Pegmatite Field, which were emplaced by magmatism during the ancient Acadian Orogeny. Pegmatites are very coarsely-crystalline, intrusive igneous rocks. Pegmatitic texture refers all or almost all the crystals in the rock being larger than 1 centimeter. Most pegmatitic-textured igneous rocks have a granitic composition, and so are called pegmatitic granites or granite pegmatites, or just "pegmatites". Pegmatites tend to form in the margins of cooling batholiths, during the final stages of a crystallization. After most of the magma has crystallized, the residual magma is rich in gas & water & silica & incompatible ions (atoms too large or too small to fit in “normal” minerals that formed earlier). Cooling of such residual magma results in pegmatites. The water-rich nature of this residual magma allows rapid ion transport during crystallization, resulting in very large crystals. The incompatible ions tend to form unusual minerals and “garbage can” minerals (e.g., beryl, chrysoberyl, columbite/tantalite, uraninite, cryolite, monazite, apatite, lepidolite, spodumene, zoisite, topaz, zircon, molybdenite, etc.). Geologic unit: Ruggles Pegmatite, Grafton Pegmatite Field, New Hampshire Plutonic Series, Devonian Locality: Ruggles Pegmatite Mine, near Grafton, southern Grafton County, western New Hampshire, USA |
Date | |
Source | Graphic granite (Ruggles Pegmatite, Devonian; Ruggles Mine, New Hampshire, USA) |
Author | James St. John |
Licensing
[edit]- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
This image was originally posted to Flickr by James St. John at https://flickr.com/photos/47445767@N05/48751570932 (archive). It was reviewed on 9 October 2019 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
9 October 2019
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 05:31, 9 October 2019 | 2,487 × 1,979 (3.18 MB) | Ser Amantio di Nicolao (talk | contribs) | Transferred from Flickr via #flickr2commons |
You cannot overwrite this file.
File usage on Commons
There are no pages that use this file.
Metadata
This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.
Camera manufacturer | Canon |
---|---|
Camera model | Canon PowerShot D10 |
Exposure time | 1/60 sec (0.016666666666667) |
F-number | f/9 |
ISO speed rating | 80 |
Date and time of data generation | 15:28, 17 September 2019 |
Lens focal length | 8.295 mm |
Width | 4,000 px |
Height | 3,000 px |
Bits per component |
|
Pixel composition | RGB |
Orientation | Normal |
Number of components | 3 |
Horizontal resolution | 180 dpi |
Vertical resolution | 180 dpi |
Software used | Adobe Photoshop Elements 16.0 (Macintosh) |
File change date and time | 17:31, 17 September 2019 |
Y and C positioning | Co-sited |
Exif version | 2.21 |
Date and time of digitizing | 15:28, 17 September 2019 |
Meaning of each component |
|
Image compression mode | 3 |
APEX shutter speed | 5.90625 |
APEX aperture | 6.34375 |
APEX exposure bias | −1 |
Maximum land aperture | 3.34375 APEX (f/3.19) |
Metering mode | Pattern |
Flash | Flash fired, compulsory flash firing, red-eye reduction mode |
Supported Flashpix version | 1 |
Color space | sRGB |
Focal plane X resolution | 16,460.905349794 |
Focal plane Y resolution | 16,483.516483516 |
Focal plane resolution unit | inches |
Sensing method | One-chip color area sensor |
File source | Digital still camera |
Custom image processing | Normal process |
Exposure mode | Manual exposure |
White balance | Auto white balance |
Digital zoom ratio | 1 |
Scene capture type | Standard |
Lens used | 6.2-18.6 mm |
Date metadata was last modified | 13:31, 17 September 2019 |
Unique ID of original document | 796D706ADCE3E4591CDC8342240D10C4 |
IIM version | 32,767 |