The purpose of preparation of rocks, minerals, ceramic, and biological specimens is most often:
Specimen types 1)+2)+3) all have “special requirements” from a materialographic point of view. Differences between the three types are characterized by surface finish and specimen thickness.
Specimen type 4 is a more conventional materialographic specimen in terms of requirements.
The same mineralogical material will have similar preparation methods across the four different specimen types, as the material characteristics are decisive for all the preparation steps.
The production of thin sections is a multistep process which requires highly specialized equipment.
Combining the equipment, the consumables, the work process, and method depends on the type of specimen. A general workflow is described. Mineralogical specimens will be described in more detail below.
1. Cutting to manageable specimen size and geometry
2. Mounting if required for reaching manageable geometry or for specimen protection.
3. Grinding/lapping to remove surface damage, reach planeness, and prepare surface for polishing.
4. Polishing to reveal the true structure and achieve surface reflectiveness.
To demonstrate our idea, we have displayed ten materials from the list below in sections of the Mineralogram. Three preparation methods are specified to cover the span of materials in the cube. Also a method for reactive or water sensitive materials is given.
How to do mineralogical and thin section preparation
Hardness is defined by the hardest mineral that makes up at least 15% of the rock.
The cube will be divided into three 2D charts, representing three levels of hardness (Mohs)
Soft 1-3
Medium 4-6
Hard 7-10
The homogeneity / heterogeneity of a rock is not determined by smaller or larger mineral content. It is related to the rock face "texture," including the internally related grain size of the minerals and their immediate appearance. To put it simply, one can say that a rock can be characterized as homogeneous if it appears structurally and compositionally uniform in all directions (uniform pattern).
Make something physically stronger and more solid
Consolidated: sticking well together – so the material becomes stronger or more solid/massive.
Interlocked grains, fracture/porous free
Unconsolidated: "loose" – porous - breaks easily – poorly cemented grains, etc.
Homogeneity and heterogeneity are concepts relating to the uniformity in a material.
Homogeneous material is uniform in composition or character – similar properties.
Heterogeneous material is distinctly non-uniform in these qualities.
