Ruby Tourmaline $3.00

Tumbled ruby tourmaline combines two distinct minerals: red or pink tourmaline (a boron silicate mineral) and, in some specimens, small inclusions or associations with corundum (ruby, aluminum oxide). These stones are polished to enhance their color and texture, making their mineral composition easier to observe. Features: Composition: Primarily tourmaline (complex borosilicate with elements like lithium, aluminum, and iron), occasionally with corundum (Al₂O₃) present as ruby. Appearance: Deep pink to reddish hues with occasional banding, zoning, or speckling; polished to a smooth finish. Formation: Develops in igneous and metamorphic environments, especially in pegmatites and high-temperature hydrothermal veins. Physical Properties: Tourmaline has a Mohs hardness of 7–7.5; ruby (if present) is harder, at 9. Both minerals are durable and resistant to weathering. Educational Value: Useful for studying complex mineral chemistry, crystal zoning, and the conditions under which different gem-quality minerals can coexist. Tumbled ruby tourmaline is a colorful and durable example of how geological processes can produce visually striking mineral combinations.