Ice Cream Quartz
Formula: Various (see below)
Origin: Africa, Democratic Republic of the Congo
Name: The name Ice Cream Quartz has been given to these beautiful specimens; the variously coloured Copper minerals and the icy Quartz crystal druse gives a collection of these specimens the appearance of ice cream.
Information: It has not been very long that these specimens from the Democratic Republic of the Congo has surfaced in the market. As a copper-mineral enthusiast these are some of the most beautiful crystal specimens I have ever seen, the colours, diversity, combinations and the additional quartz-druse coating makes these very special collectible specimens.
Similar looking material is known from the Lily Mine in Peru (South America), but the new material from DRC exceeds these known specimens by far in combinations and the various different mineral combinations that can be found. The specimens may either be "plain" with a singular copper-mineral covered with Quartz crystal druse (see images below) or may be far more complex with various minerals in one specimen (see images on the right).
In most cases the copper-minerals are covered in Quartz druse, but in some, these minerals (mostly Dolomite and unusual Malachite crystal-formations) formed on top of the Quartz druse.
We have managed to get hold of very nice material (a great selection of specimens) on two occasions, these were said to come from Kimpese (a) and Kakanda (b).
Unusual Malachite crystal formation on Quartz druse covering Plancheite and Cobaltoan Calcite
Malachite and unusual Dolomite crystal formations on Quartz druse covering Cobaltoan Calcite
Some colour variation of Ice Cream Quartz
Minerals of Ice Cream Quartz
Quartz - SiO2
The clear Quartz druse can take on various colours due to the underlying Copper minerals. This can vary in shades of brown, green, blue, pink, purple, grey, white and clear. The quartz crystals may also have inclusions of these minerals.
Cobaltoan Calcite - (Ca,Co)CO3
This beautiful pink mineral is generally found underlying the Quartz druze. It is often found in association with Malachite, Dolomite and the blue Copper minerals.
Chrysocolla - Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O
There are at least two different blue copper minerals found in Ice Cream Quartz. It appears as if Plancheite and Chrysocolla is present. Shattuckite is also known from these areas and is also possible.
Heterogenite - Co3+O(OH)
A normally blackish cobalt oxide mineral, often found in association with Cobaltoan Calcite, Malachite and Chrysocolla.
Kolwezite - (Cu,Co)2(CO3)(OH)2
A rare khaki to dark green mineral that is found in small spherical formations. It has only been observed in a limited number of specimens underneath the Quartz druse.
Malachite - Cu2(CO3)(OH)2
One of the best known Copper minerals, famed for its beautiful rich and metallic green colour. It can either be found as growths in the matrix, as inclusions in the Quarts or in various crystal formations on top of the Quartz druse.
Plancheite - Cu8(Si8O22)(OH)4 · H2O
A light powder-blue coloured mineral, often found in association with Malachite and Cobaltoan Calcite, covered by Quartz crystal druse.
Dolomite - CaMg(CO3)2
Usually found as white spherical to botryoidal like growths on top of the Quartz druse.