Secilit

Secilit is not a standard term with a fixed scientific definition in widely used English-language literature. In many cases, it appears as a misspelling or variant of selenite, the transparent variety of gypsum, or as a transliteration variant in Turkish or other languages. Without additional context, it is difficult to attribute a precise meaning to the word.

The closest widely recognized term is selenite. Selenite is a mineral, one of the crystalline varieties of gypsum, with the chemical formula CaSO4·2H2O. It forms through the evaporation of sulfate-rich waters and occurs in sedimentary rock formations, commonly in evaporite deposits. Selenite crystals are typically colorless to white and can be transparent, often forming tabular to bladed shapes. It has a Mohs hardness of about 2, perfect cleavage in one direction, and a vitreous luster. Selenite is found in numerous localities around the world, including regions in Mexico, Spain, and the United States, among others.

In addition to its geological interest, selenite crystals are valued by collectors for their clarity and have historically been used in decorative objects and, in some cultures, for window panes. The name selenite derives from the Greek selene, meaning moon, in reference to the moonlike appearance of clear crystals.

If you intended a different sense of "secilit" (for example, a proper noun, organization name, or a term in another language), please provide more context to refine the article.