HSN Code 2515 refers to "Marble, travertine, ecaussine and other calcareous monumental or building stone of an apparent specific gravity of >= 2,5, and alabaster, whether or not roughly trimmed or merely cut, by sawing or otherwise, into blocks or slabs of a square or rectangular shape (excluding in the form of granules, chippings or powder)." This classification code is essential for identifying natural stones used in construction and monumental works for import/export purposes based on their nature, composition, and intended use. Common products under HSN Code 2515 include polished marble slabs, travertine tiles, ecaussine blocks, and alabaster pieces. Additionally, the GST rate for these building stones under this code supports accurate trade compliance.