Burkeite is a rare carbonate-sulfate mineral typically found in the evaporite deposits of ancient or active alkaline salt lakes. Collectors prize it for its unique, often slightly rounded dipyramidal crystal forms, which are most famously associated with the brine deposits of Searles Lake in California.
Is this burkeite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch burkeite with a known reference. Burkeite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous to greasy.
- 4Match the color rangeCompare against the expected color range: white, gray, gray white, light brown, pink.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: massive, nodular, tabular.
Often confused with
Burkeite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside burkeite
Minerals reported to co-occur with burkeite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₄(SO₄)(CO₃)
- Mohs hardness
- 3.5
- Density
- 2.57 g/cm³
- Streak
- White
- Luster
- Vitreous to greasy
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Massive, nodular, tabular
- Cleavage
- Indistinct
- Fluorescence
- Yellow-white under SW and LW UV
- Rarity
- Rare
- Uses
- Collector, Research
- Host rock
- An uncommon product of evaporation in dry lakes, but typical of efflorescences on saline soils
Where rockhounds find burkeite
Classic worldwide localities
- Searles Lake, San Bernardino Co. and Deep Spring Lake, Inyo Co., California, USA
- Carbonate Lake, Grant Co., Washington, USA
- Teels Marsh, Esmeralda Co., Nevada, USA
- Green River Formation, northern Piceance Creek Basin, and at Hortense and Mount Princeton Hot Springs, along Chalk Creek, Chaffee Co., Colorado, USA
- Lake Katwe, western Uganda
- Loiengalani, Lake Turkana, Kenya
Field-hunting tip
Where it forms: An uncommon product of evaporation in dry lakes, but typical of efflorescences on saline soils. If you start seeing gaylussite, trona, sulfohalite in float, you are in the right ground. Typical habit: massive, nodular, tabular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify burkeite?+
Where is burkeite found?+
What rocks look like burkeite?+
What minerals are found with burkeite?+
What kind of rock does burkeite form in?+
What is burkeite used for?+
Find burkeite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
