Sand deposits found on beaches or in rivers and streams, are mostly quartz (silicon dioxide, SiO2) grains. Weathering of rocks such as granite forms these quartz grains. In the process of weathering, the softer, weaker minerals in granite (such as feldspar) are weathered away. The more resistant quartz eventually is ground down in size, but does not break down chemically. In time, these quartz grains accumulate in rivers, streams, deltas and on beaches.
Stone is considered by many to be the premium material in all kinds of construction. Its use dates to the dawn of civilization, and only buildings made of stone have survived from ancient times. Dimension Stone is stone that is cut and finished to specified sizes and shapes, which can be used for buildings, monuments, paving, furniture, and decorative objects. Sometimes called cut stone, it is typically quarried in rectangular blocks, then sawed and finished to specification.
The term diatomite is applied both geologically and commercially to the nearly pure sedimentary accumulation of diatom frustules—the microscopic skeletons of unicellular aquatic algae belonging to the class of golden brown algae, Bacillariophyceae. The sediments are fine-grained, highly siliceous, and consist primarily of amorphous opaline silica with only minor amounts of organic residue, secondary minerals, and co-deposited nondiatomaceous or crystalline clastic debris. Synonyms in current usage include diatomaceous earth and kieselghur. More antiquated and obsolete terminology includes tripoli powder, tripolite, and infusorial earth.
Crushed stone is used as aggregate in construction material uses. The most common types of rock processed into crushed stone include limestone, dolomite, granite, and traprock. Smaller amounts of marble, slate, sandstone, quartzite, and volcanic cinder are also used as construction aggregates.
Even though no standard definition of the term “clay” is accepted by geologists, agronomists, engineers, and others, the term is generally well-understood by those who use it. Clay is an abundant, naturally occurring, fine-grained material composed predominantly of hydrous aluminum silicates.
Clay is not a single mineral, but a number of minerals. Clays fall into six general categories: kaolin, ball clays, fire clays, bentonite, common clays and Fuller’s earth. Clays are common all over the world. Some regions produce large quantities of specific types of clay. The United States is self-sufficient so it imports only small amounts of clay.
Cement is a powdery substance made with calcined lime and clay. It is mixed with water to form mortar or mixed with sand, gravel, and water to make concrete, one of the world’s most versatile building materials.