File:Tiger's eye quartz 12.jpg
Original file (3,601 × 1,819 pixels, file size: 6.24 MB, MIME type: image/jpeg)
Captions
Summary
[edit]DescriptionTiger's eye quartz 12.jpg |
English: Tiger's eye quartz (cut surface)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5900 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates. The silicates are the most abundant and chemically complex group of minerals. All silicates have silica as the basis for their chemistry. "Silica" refers to SiO2 chemistry. The fundamental molecular unit of silica is one small silicon atom surrounded by four large oxygen atoms in the shape of a triangular pyramid - this is the silica tetrahedron - SiO4. Each oxygen atom is shared by two silicon atoms, so only half of the four oxygens "belong" to each silicon. The resulting formula for silica is thus SiO2, not SiO4. The simplest & most abundant silicate mineral in the Earth's crust is quartz (SiO2). All other silicates have silica + impurities. Many silicates have a significant percentage of aluminum (the aluminosilicates). Quartz (silicon dioxide/silica - SiO2) is the most common mineral in the Earth's crust. It is composed of the two most abundant elements in the crust - oxygen and silicon. It has a glassy, nonmetallic luster, is commonly clearish to whitish to grayish in color, has a white streak, is quite hard (H≡7), forms hexagonal crystals, has no cleavage, and has conchoidal fracture. Quartz can be any color: clear, white, gray, black, brown, pink, red, purple, blue, green, orange, etc. The specimen seen here is tiger's eye, a distinctive and attractive, semi-precious variety of quartz consisting of closely-packed, straight to slightly wavy fibers of quartz. The yellowish-brown coloration is apparently due to limonite (= hydrous iron hydroxy-oxide). Tiger's eye quartz has chatoyancy - tilting the specimen in bright light results in an optical effect of moving colors and varying light intensity. Tiger's eye quartz is traditionally hypothesized to have formed by quartz and limonite replacement of asbestiform amphibole. Another hypothesis, proposed in the 2000s, suggests that the quartz fibers grew perpendicular to the walls of a slowly-dilating fracture. Photo gallery of tiger's eye quartz: www.mindat.org/gallery.php?min=3960 |
Date | |
Source | https://www.flickr.com/photos/47445767@N05/53485740166/ |
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@N05/53485740166. It was reviewed on 26 March 2024 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
26 March 2024
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 17:19, 26 March 2024 | 3,601 × 1,819 (6.24 MB) | Ser Amantio di Nicolao (talk | contribs) | Uploaded a work by James St. John from https://www.flickr.com/photos/47445767@N05/53485740166/ with UploadWizard |
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 | 1/200 sec (0.005) |
F-number | f/3.5 |
ISO speed rating | 80 |
Date and time of data generation | 21:33, 24 January 2024 |
Lens focal length | 9.681 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 20.0 (Macintosh) |
File change date and time | 23:07, 24 January 2024 |
Y and C positioning | Co-sited |
Exif version | 2.21 |
Date and time of digitizing | 21:33, 24 January 2024 |
Meaning of each component |
|
Image compression mode | 3 |
APEX shutter speed | 7.65625 |
APEX aperture | 3.625 |
APEX exposure bias | −0.66666666666667 |
Maximum land aperture | 3.625 APEX (f/3.51) |
Metering mode | Pattern |
Flash | Flash did not fire, compulsory flash suppression |
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 | 18:07, 24 January 2024 |
Unique ID of original document | B17E7AAD6697FD9E21EFE12B63E8731D |