Crystals

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General Information

Bismuth

Bismuth is one of the elements from the table of elements. Bismuth has a rare type of crystals: hoppered crystals. They are even rarer in nature. When the crystalization proces is conducted with great care, the most wonderfull crystals can be made.

The colour of the crystals is caused by a thin layer of bismuth oxide, that is formed when bismuth comes in contact with oxygen at the right temperature. The colour can be any colour from the rainbow, but in general some colours are more abundant than others. There are crystals that are mostly composed of blue and purple, or blauw and green with some yellow.

The purity of the bismuth also determines the colour and shape of the crystals. The purity that normally is used for laboratory grown crystals is 99.95% or higher.[1]

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Production Methods

Bismuth crystals are made by melting bismuth and then letting it cool down again. Crystallization will take place and the crystals will start growing. Depening on the volume you use for the molten bismuth, you can either empty it, removing the uncrystallized bismuth (still liquid) or you can take the crystals out of the melt with a pair of tweezers. The crystals have a tendency to float, because the density of liquid bismuth is higher than that of solid bismuth.[1]

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Chemical & Physical Information

Trivial nameBismuth
Chemical nameBismuth
Other namesWismut (DE), Bismut (NL,BE)
Type of chemicalElement
SymbolBi
Element number83
Element categoryPoor metals
Group, period, block15, 6, p
CAS number7440-69-9
Crystal systemTrigonal
Bravais latticeRhombohedral
Coordination geometryOctahedral
Hardness (Mohs)2.25
Young's modulus32 GPa
ColourSilver
LusterMetallic
StreakGrey
OpacityOpaque
Safety summarySafe
Safety dataMSDS
Production methodFrom melt
StorageNothing special.
ExtraColour formed by layer of bismuth oxide and it's diamagnetic.

For more information, also look at the bismuth chemicals and the bismuth minerals.

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Photos

Bismuth

(3 cm)

Bismuth

(3 cm)

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Sources

[1] Wikipedia

[2] Specimen from my personal collection, photo taken by me.