Obeliskide

Obeliskide is a hypothetical mineral described here for illustrative purposes. It is characterized by elongated, obelisk-shaped crystals, often forming radiating or columnar aggregates within granitic and pegmatitic rocks.

Chemistry and structure: Obeliskide is described as a complex aluminosilicate, with silicon and aluminum forming the framework and calcium and sodium acting as large-cation reservoirs. Reported compositions place calcium and sodium as dominant interstitial cations, with trace amounts of iron, magnesium, and potassium. The mineral is often linked to a monoclinic crystal system in discussions of its hypothetical structure.

Physical properties: In the proposed description, obeliskide crystallizes as prismatic, elongated crystals. Hardness is estimated around 6 on the Mohs scale; color ranges from colorless to pale yellow or gray; luster is vitreous; and transparency ranges from transparent to translucent. Cleavage and fracture are described as imperfect or distinct on certain crystal faces in illustrative accounts.

Occurrence and formation: Obeliskide is said to form in late-stage hydrothermal environments within granitic pegmatites, commonly associated with quartz, feldspar, muscovite, and other aluminosilicates. The formation is imagined to occur under moderate temperature and low to moderate pressure, with radiating or columnar growth favored by a directional mineral environment.

Classification and research: Because obeliskide is a hypothetical mineral, there is no formal, real-world classification or extensive provenance data outside this article. In fictional contexts, it serves to exemplify crystal habit diversity and the nomenclature of obelisk-like minerals.