ASTM F3419-22

SIGNIFICANCE AND USE 5.1 Petrographic examinations are made for the following purposes: 5.1.1 To determine the mineralogy of the material that may be observed by petrographic methods (in this method, by use of XRD) and that may have a bearing on the performance of the material in its intended use. 5.1.2 To determine the relative amounts of the constituents of the sample which is essential for proper evaluation of the sample when the constituents may differ significantly in properties that have a bearing on the performance of the material in its intended use. 5.1.3 This method helps to evaluate mineral aggregate sources for suitability as a material to be used for construction, renovation, or modification of equine surfaces. The information gathered will allow for the comparison of the composition of new mineral sources with samples of other mineral aggregate from one or more sources, for which test data or performance records are available. 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 petrographer’s 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. SCOPE 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 user’s needs. 1.5 This standard does not purport to address all of the safety c...