Hilgardite

Chemical formula (IMA record)

Ca₂B₅O₉Cl(H₂O)

Recognition status

Grandfathered

Original-description year in master list

1937

First-discovery country (IMA)

United Kingdom

Crystal system

Not supplied in the IMA master list

Mohs hardness

Not supplied in the IMA master list

Measured density

Not supplied in the IMA master list

Historical discoverer

Not supplied in the IMA master list

How it occurs in nature

This species has a documented chemistry and recognition record in the IMA catalog. The master list does not describe its formation environment. Consult the cited mineral-description studies below for species-specific occurrence and geological context; these cannot be inferred reliably from the formula alone.

Discovery & scientific record

The country refers to the master list’s first-discovery country, using modern borders. It is not a list of all deposits. A question mark is retained when the source is uncertain; a special-procedure date can refer to redefinition rather than discovery.

Catalog coverage and profile depth are different: every species in the cited IMA edition is indexed, but this edition does not provide every physical property or a full discovery narrative. The archive leaves those gaps explicit. Formulae and references are adapted from the IMA list under CC BY-SA 3.0; consult the original page for authoritative typography.