Borate and tungstate minerals

Minerals whose anion group is borate (BO₃ / BO₄) or tungstate (WO₄): sinhalite, howlite and scheelite.

What this family is

Classified by formula: sinhalite (MgAl(BO₄)) and howlite (Ca₂SiB₅O₉(OH)₅) are borates and scheelite (Ca(WO₄)) is a tungstate, so none of the three is a silicate or a sulfate. Howlite contains silicon but is still classed as a borate.

The Geological Survey of Japan specimen catalogue divides them differently: borates share one class with nitrates and carbonates, and tungstates share one with sulfates, chromates and molybdates; this site lists borates and tungstates together by anion.

Scope of this family

Minerals whose anion group is borate (BO₃ / BO₄) or tungstate (WO₄): sinhalite, howlite and scheelite.

Member entries (3)

Treatments recorded on member entries

This table scrolls sideways on narrow screens.

Treatment	Member entries	Disclosure requirement
Dyed	Howlite	Must be disclosed. Dye may fade, bleed or dissolve in solvents (alcohol, acetone), and dyed material must not be labelled "natural colour"; dyed jadeite counts as B/C jade and must be conspicuously labelled; dyed agate and chalcedony are extremely common.

Care codes on member entries

Member entries cite these CIBJO special-care codes: special-care code a, special-care code c, special-care code j, special-care code k. General gem care gives the full wording of every code.

Where members are recorded

Some member entries record the localities where their materials are found; Recorded localities shows them on a sketch map and lists them by continent.

Names

简体中文: 硼酸盐与钨酸盐矿物
繁體中文: 硼酸鹽與鎢酸鹽礦物
English: Borate and tungstate minerals
日本語: ホウ酸塩・タングステン酸塩鉱物

Authority source

Authority source

Review status

Reviewed against CIBJO, GB/T and IMA boundaries.

Shared classification

All 3 members share these values:

Origin class: Natural materials
Material domain: Natural inorganic gem materials
Identity level: Mineral species
Mineral chemical class: Borates and tungstates
Construction or treatment status: Natural identity; treatment status unknown