The ICDD database are commercial and can be purchased directly from their web site: http://www.icdd.com/.

Other non commercial options:

* From the university of Arizona: http://rruff.geo.arizona.edu/AMS/amcsd.php

* the crystallography open source database (COD): http://www.crystallography.net/

Hope this helps. Sample preparation is of key importance to determine mineralogy and clay mineralogy by XRD with reasonable accuracy, there are many publications on the topic and several books that can help. One book I find very useful is: 'X-Ray Diffraction and the Identification and Analysis of Clay Minerals' by Moore and Reynolds.

sir Kenneth M Towe , i mean complete d-spacing values of clay and non-clay minerals

thanks Debora Berti. but there is no alternate to get ICDD file free of cost?

I'm not aware of ways to get the ICDD database for free. However, the other options I listed do have structure files of many of the minerals that are commonly found in rocks. Even the ICDD database does not include all clay minerals that are found in shale. What method of quantification do you use?

Thanks Debora Berti. i have observed d-spacing and need standard d-spacing in order to develop shale mineralogy. i am evaluating shale for shale gas potential, for this purpose shale mineralogy is very significant.   

Saeed,

If you have a specific XRD pattern that you're trying to interpret, you can share it as an attachment in the question or send it to me via researchgate message. If you choose this route, please save the data as a text file that include intensity (preferably counts per seconds) and 2-theta angle (or d-space) information.

Commonly shale contains quartz, K-feldspars, plagioclase and calcite as main non clay minerals. Common accessory minerals are pyrite and apatite.These minerals are found in all the above databases (e.g. quartz: http://rruff.geo.arizona.edu/AMS/xtal_data/DIFfiles/00859.txt). The University of Bari (Italy) has an open software for searching minerals that already includes a mineral database (they ask for registration as a user):

wwwba.ic.cnr.it/content/qualx

It is difficult -and not always possible- to identify clay minerals solely on the basis of the powder XRD pattern of the whole sample. This is particularly true if you need to identify mixed layer clay (e.g. illite/smectite) and need to estimate expandability. To this purpose it is best to separate the clay and run an additional XRD pattern on an 'oriented' sample.

Clays are separated by first dispersing the sample in water and dispersant (I use sodium carbonate), the sample in solution is then left to settle in a graduated cylinder for the time it takes for particles larger than 2 micron to settle below the depth at which the clay sample is taken (with a pipette). The Stokes law is used to calculate the time required for the larger particles to settle. Note, that many labs use a centrifuge rather than a graduated cylinder to separate the clay faster, get better dispersion and be able to 'wash' samples. Also note, that because the Stokes law is valid for spherical particles while clays have a platy shape, the 2 micron is a nominal diameter used by clay scientists and engineers.

The clay sample in the pipette needs to be carefully put on a slide and let dry before running the XRD. Because clay minerals are platy they will orient, and the XRD pattern will show their 00l spacing.

The USGS has a flow chart that can help identify clay minerals based on the d-space of oriented slides and guides through other treatments that may be necessary:

http://pubs.usgs.gov/of/2001/of01-041/htmldocs/flow/index.htm

For shale, treatment with ethylene glycol is necessary to identify smectite and/or mixed layer illite/smectite. The USGS chart is more helpful than a database for clay mineral identification.

Thanks Debora Berti, for your prosper help. Actually i just needed the link of USGS (http://pubs.usgs.gov/of/2001/of01-041/htmldocs/flow/index.htm ) that you provided. 

Saeed,

the books mentioned above by Moore and Reynolds and Brindley are Brown should be your key starting points.  In its current form the ICDD PDF file is not that useful for the identification of clay minerals, its main use would be the identification of the non-clay minerals that occur with clays, so its not at all essential that you have it to hand.  If you don't have access to the above books the Rockjock spreadsheet of Denny Eberl contains a sheet ('common lines') that reproduces the useful list of mineral spacings from Brindley and Brown and you can download the spreadsheed here

ftp://brrcrftp.cr.usgs.gov/pub/ddeberl/RkJock%2011/

Additionally, you can search online for a copy of  Chen....Table of Key Lines in X-ray Powder... and you will find a text that is still useful for identification of minerals that can occur along with clays.

However as mentioned above clay identification is a specialised field, but I emphasise again that the two books mentioned above will ensure you start on, and then keep you on, the right track.

sincerely,

steve

Thanks Stephen Hillier.