Quartz (Var: Chalcedony) : SiO2

How to use the mindat.org media viewer

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Welcome to the mindat.org media viewer. Here is a quick guide to some of the options available to you. Different controls are available depending on the type of media being shown (photo, video, animation, 3d image)

Controls - all media types

Zoom in and out of media using your mousewheel or with a two-finger 'resize' action on a touch device.

Use the mouse or your finger to drag the image or the view area of the image around the screen.

< and > at the left and right hand side of the screen move forwards and backwards for the other images associated with the media you selected. Usually this is for further photos of the same specimen. Keyboard shortcuts: use the left and right arrow keys.

> in the bottom center, raises the information box giving details and further options for the media, < at the top of this box then hides it. Keyboard shortcuts: use the up and down arrow keys.

? opens this help window. Keyboard shortcuts: use the H key or the ? key.

Other keyboard shortcuts:

1Fit image to screen
2Fill screen with image
5Display at full resolution
<Make background darker
>Make background lighter
spaceHide/dim titles and buttons

Controls - Video

Video files have a standard set of video controls: - Reset to start, - Skip back, - Play, - Pause, - Skip forwards. Keyboard shortcuts: You can stop/start video play with the P key.

Controls - Animation (Spin Rotation)

Animation (usually 360 degree spin rotations) have their own controls: - enable spin mode. Note that while images are loading this option will not be available but will be automatically activated when the animation has loaded. Once active you can spin the image/change the animation by moving your mouse or finger on the image left/right or by pressing the [ or ] keys.

The button switches to move mode so that you can use your mouse/fingers to move the image around the screen as with other media types.

The button, or the P key will start playing the animation directly, you can interrupt this by using the mouse or finger on the image to regain manual movement control.

Controls - 3D Stereoscopic images

Stereoscopic 3D image viewing requires a suitable 3D television or monitor correctly configured for your computer. Passive 3D systems such as LG 3DTVs are the easiest to configure for this.

To enable/disable 3D stereo display of a compatible stereo pair image press the 3 key. If the left/right images are reversed on your display (this often happens in full-screen mode) press the 4 key to reverse them.

Summary of all keyboard shortcuts

1Fit image to screen
2Fill screen with image
3Switch to 3D display of stereo pair
4Switch left/right images in 3D mode
5Display at full resolution
<, >Make background darker/lighter
H or ?Show/hide this help page
PPlay/Pause Video or Animation
[, ]Backwards/forwards one frame (Animation only)
up arrowShow information box
down arrowHide information box
left arrowPrevious image/media page
right arrowNext image/media page
spaceHide/dim titles and buttons

Copyright © Amir C. Akhavan
minID: KKC-EM8

Quartz (Var: Chalcedony) : SiO2

Copyright © Amir C. Akhavan  - This image is copyrighted. Unauthorized reproduction prohibited.

A small piece of silicified limestone with secondary fillings of blueish chalcedony in the voids in between. The blueish chalcedony (see second photo shot in incandescent light) shows a rather strong fluorescence of green color in short-wave UV light. Some of the chalcedony shows a botryoidal habit and can also be overgrown by small quartz crystals. In these cases the fluorescence shows a banding that coincides with the agatoid banding seen in the wall-lining chalcedony. The creme-colored parts are completely silicified (no calcite is left in the matrix), resemble porcelain in places and are almost opaque. They show a white and blueish white fluorescence. Pure blue patches are reflections of the UV lamp.
Width of the specimen: 7cm.
UV photo white balanced to 5000K.
Found in April 2010 in the rubble at the road cut shown in the locality photos. Collection Alfredo Petrov.

This Photo was Mindat.org Photo of the Day - 26th Oct 2011

This photo has been shown 3498 times
Photo added:27th Apr 2010
Dimensions:1024x809px (0.83 megapixels)

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