Quartzite

Hardness: 7 (Mohs scale), Color: Pink, reddish, and yellowish-cream, Luster: Vitreous to greasy, Crystal structure: Massive (interlocking quartz grains), Cleavage: None

Formed from quartz-rich sandstone that has been subjected to high heat and pressure, typically during tectonic plate collisions. The reddish hues suggest the presence of iron oxides (hematite) during metamorphism. It has been rounded by natural water tumbling, likely in a river or beach environment.

Used historically for stone tools due to its conchoidal fracture. Today used for decorative stone, landscaping gravel, railway ballast, and sometimes as a minor source of silica. Small, attractive tumbled pieces are collected by hobbyists.

Quartzite is so hard and durable that it often forms ridges and peaks in mountainous areas because it resists weathering better than surrounding rocks. The prominent criss-crossing veins are likely quartz that filled fractures after the rock was initially formed.

Identified by its granular, sugary texture (though less obvious when smooth/tumbled), hardness (can scratch glass), and lack of cleavage. Often found in areas with past tectonic activity, in riverbeds, or glacial deposits where durable rocks survive transport. Great tumbling rough.