ASTM F3419-22

5.1?Petrographic examinations are made for the following purposes:

5.2?This method may be used by a petrographer employed directly by those for whom the examination is made. The employer should tell the petrographer, in as much detail as necessary, the purposes and objectives of the examination, the kind of information needed, and the extent of examination desired. Pertinent background information, including results of prior testing, should be made available. The petrographers advice and judgment should be sought regarding the extent of the examination.

5.3?This method may form the basis for establishing arrangements between a purchaser of consulting petrographic service and the petrographer. In such a case, the purchaser and the consultant should together determine the kind, extent, and objectives of the examination and analyses to be made and should record their agreement in writing. The agreement may stipulate specific determinations to be made, observations to be reported, funds to be obligated, or a combination of these or other conditions.

1.1?X-Ray diffraction (XRD) is a tool for identifying minerals, such as quartz and feldspar, and types of clay present in bulk samples of equine surfaces. Determining the mineralogy of a given bulk sample provides insight into surface properties, such as abrasion resistance by comparing the relative differences of hardness of the various mineral fractions such as quartz or feldspar or the plasticity differences in clay minerals such as smectite or kaolinite. XRD techniques are qualitative in nature and only semi-quantitative.

1.2?Particle size distribution analyses methods including hydrometer tests to determine proportions of sand, silt, and clay fractions based upon particle size but are not able to distinguish particles by shape or mineralogy of materials. In addition to a qualitative detection of minerals present in a sample, XRD methods are also semi-quantitative and also yield important data on the relative proportion of particular minerals present.

1.3?XRD techniques are generally semi-quantitative in nature. Even so, such semiquantitative data is useful in determining relative proportions of each mineral type. This method is also semi-qualitative in nature as it is geared for the determination or mineral groups. For example, it will determine the relative amount of alkali feldspars (such as K-feldspar or Nafeldspar) from Plagioclase-feldspar but not necessarily if the Plagioclase-feldspar is albite or anorthite nor whether the K-feldspar is orthoclase of microcline. Likewise, it will differentiate smectite from mica from kaolinite but not whether the smectite is montmorillonite or saponite. More precise determination of mineral species by XRD is possible but involves more advanced preparation and treatment methods than what is within the scope of this standard.

1.4?The XRD method herein primarily makes use of Glass Slide Method but may be subject to modification depending on the users needs.

1.5?This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.