Mila'sExotic Plants & CuriositiesA living collection by Luminary OdditiesThe mineral atlas
Investigate colorful mineral materials through their chemistry, structure, formation, and documented human uses. Color is a starting point for observation; the individual guides explain identity and treatment.
12 specimens · Geology, history, and attributed traditions
The cubic garden
Calcium fluoride (CaF2).
Fluorite is calcium fluoride, often seen as cubes or color-zoned masses. Purple, green, yellow and blue can share one piece. A broken octahedron and a naturally grown cube have different origins of shape.
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Slanting planes
Calcium carbonate (CaCO3).
Calcite is calcium carbonate, appearing as clear cleavage fragments, pointed crystals, rounded growths and banded carving stone. One mineral supports far more shapes than the familiar tumble. A rhombohedral fragment is not a cube despite its regular-looking faces.
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A radiating star
A calcium-carbonate polymorph distinct from calcite.
Aragonite is calcium carbonate with a structure distinct from calcite. Star-like clusters, branches and banded masses show that one mineral can have many external forms. A radiating cluster is an aggregate rather than one simple pointed crystal.
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Clear plates and silken fibers
Hydrated calcium sulfate (CaSO4·2H2O).
Gypsum is hydrated calcium sulfate, with clear selenite, fibrous satin spar and fine-grained alabaster expressing very different textures. A clear plate and a silky wand can share a mineral species while deserving different variety labels.
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A quiet blue mass
Trade name for blue-grey massive anhydrite.
Angelite is a trade name for blue-gray massive anhydrite. Its soft-looking opaque surface differs from a clear celestine cluster. The sky-like color and angelic name are appearance and naming features rather than chemical identity.
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Pale blue geode light
Strontium sulfate (SrSO4).
Celestine is strontium sulfate, also commonly called celestite. Pale blue crystal clusters are familiar, but the mineral occurs in other colors. A cavity-lined cluster preserves a relationship between crystals and host rather than one giant solid gem.
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Heavy pale plates
Barium sulfate (BaSO4).
Barite, also spelled baryte, is barium sulfate. Broad plates, radiating groups and rose-like forms give it a wide visual range. Its substantial heft is a useful characteristic, but should not be replaced by a destructive test or guessed from an image.
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A blue green prism
A mineral-group name; much gem material is fluorapatite.
Apatite is a mineral-group name, not an identity assigned by blue color.
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Green concentric worlds
Copper carbonate hydroxide.
Malachite’s polished green ribbons are only one face of the mineral.
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Deep copper blue
Blue copper carbonate hydroxide.
Azurite is the blue copper carbonate hydroxide Cu3(CO3)2(OH)2.
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Copper blue in the matrix
Copper-bearing hydrated silicate material, often intermixed with other minerals.
Chrysocolla is a name to read with the host.
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A sky colored network
Hydrated copper aluminium phosphate.
Turquoise is hydrated copper aluminium phosphate, not a name for everything blue-green.
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