File:Amethyst-milky quartz (Diamond Hill, Ashaway Village, Hopkinton, Rhode Island, USA) 5 (32109621613).jpg
![File:Amethyst-milky quartz (Diamond Hill, Ashaway Village, Hopkinton, Rhode Island, USA) 5 (32109621613).jpg](https://upload.wikimedia.org/wikipedia/commons/thumb/c/c3/Amethyst-milky_quartz_%28Diamond_Hill%2C_Ashaway_Village%2C_Hopkinton%2C_Rhode_Island%2C_USA%29_5_%2832109621613%29.jpg/586px-Amethyst-milky_quartz_%28Diamond_Hill%2C_Ashaway_Village%2C_Hopkinton%2C_Rhode_Island%2C_USA%29_5_%2832109621613%29.jpg?20191205020419)
Original file (2,588 × 2,648 pixels, file size: 3.53 MB, MIME type: image/jpeg)
Captions
Captions
Summary
[edit]DescriptionAmethyst-milky quartz (Diamond Hill, Ashaway Village, Hopkinton, Rhode Island, USA) 5 (32109621613).jpg |
Quartz from Rhode Island, USA. 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 about 5400 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. Purple quartz is called amethyst. The coloring agent for amethyst is not agreed upon. Some workers say that it is due to Fe+4 impurity, some say the impurity is Fe+3, and others say it is Mn. The crystalline quartz plate from Rhode Island shown above consists of amethyst on milky quartz. Research has shown that the two quartz types precipitated at disparate times, but both have an epithermal meteoric origin - the silica precipitated from fluids ultimately derived from rainwater. The quartz apparently formed along conduits in quartzites of the Plainfield Formation (Proterozoic). Locality: excavation at Diamond Hill, Ashaway Village, south of Hopkinton, southwestern Washington County, southwestern Rhode Island, USA Photo gallery of quartz and amethyst: <a href="http://www.mindat.org/gallery.php?min=3337" rel="nofollow">www.mindat.org/gallery.php?min=3337</a> and <a href="https://www.mindat.org/gallery.php?min=198" rel="nofollow">www.mindat.org/gallery.php?min=198</a> Site-specific info. synthesized from: Rakovan et al. (1995) - Amethyst on milky quartz from Hopkinton, Rhode Island. Mineralogical Record 26(2): 83-89. |
Date | |
Source | Amethyst-milky quartz (Diamond Hill, Ashaway Village, Hopkinton, Rhode Island, USA) 5 |
Author | James St. John |
Licensing
[edit]![w:en:Creative Commons](https://upload.wikimedia.org/wikipedia/commons/thumb/7/79/CC_some_rights_reserved.svg/90px-CC_some_rights_reserved.svg.png)
![attribution](https://upload.wikimedia.org/wikipedia/commons/thumb/1/11/Cc-by_new_white.svg/24px-Cc-by_new_white.svg.png)
- 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@N05/32109621613 (archive). It was reviewed on 5 December 2019 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
5 December 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 | 02:04, 5 December 2019 | ![]() | 2,588 × 2,648 (3.53 MB) | Ser Amantio di Nicolao (talk | contribs) | Transferred from Flickr via #flickr2commons |
You cannot overwrite this file.
File usage on Commons
The following page uses 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/14 |
ISO speed rating | 80 |
Date and time of data generation | 13:27, 3 May 2014 |
Lens focal length | 18.6 mm |
Orientation | Normal |
Horizontal resolution | 180 dpi |
Vertical resolution | 180 dpi |
Software used | Adobe Photoshop CS2 Macintosh |
File change date and time | 18:22, 15 February 2017 |
Y and C positioning | Co-sited |
Exif version | 2.21 |
Date and time of digitizing | 13:27, 3 May 2014 |
Meaning of each component |
|
Image compression mode | 3 |
APEX shutter speed | 5.90625 |
APEX aperture | 7.625 |
APEX exposure bias | 0 |
Maximum land aperture | 4.59375 APEX (f/4.91) |
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 | Auto exposure |
White balance | Auto white balance |
Digital zoom ratio | 1 |
Scene capture type | Portrait |
Supported Flashpix version | 1 |
Image width | 2,588 px |
Image height | 2,648 px |
Date metadata was last modified | 13:22, 15 February 2017 |
IIM version | 2 |