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last edited: 12/22/15
One of the very best chemicals for growing crystals is copper sulfate. The
only trouble with it is that is a poisonous chemical compound. Because of its
poisonous nature, it has been used to kill tree roots in sewers. A solution of
copper sulfate is simply flushed down the toilet to kill tree roots. In some cases
this treatment turned out to cause more harm than good. If the sewer pipes were
made out of cast iron, the copper sulfate reacted with the iron, causing the iron to
go into solution and precipitating tiny copper crystals in the process. The tiny
copper crystals were then usually washed away by subsequent flushing, but
larger holes were created in the iron pipes that allowed larger roots to grow in the
pipes at a later time. Because of its use in killing tree roots, copper sulfate can be
purchased in hardware and plumbing supply stores.
So, if you wish to grow copper sulfate crystals, you must seriously emphasize
the fact to your students that the chemical is poisonous and that they must wash
their hands after working with this chemical. One factor helping in the safety of
using this material is that even in dilute solutions it has a very bad taste.
sulfate responds well to the supersaturation technique is which you
dissolve as much copper sulfate as possible in boiling hot water and then allow it
slowly cool. Nice crystals can form in as little as 4 to 6 hours. Warning! Copper
sulfate chemically reacts with iron, so do not try try to warm a solution in a stainless
steel kettle. One of the videos listed at the bottom of this page shows crystals of
copper sulfate that were grown in four hours by the supersaturation technique.
sharpest and clear copper sulfate crystals form by the evaporation
process. Just prepare a saturated solution (in which you have dissolved as much
copper sulfate that you can in water). Carefully and slowly pour this solution into
a clean glass or plastic container, making sure that any undissolved crystals are
left behind in the first container. Any crystals that are transferred to the new
container will become seed crystals that will trigger off the formation of crystal
growth. Too many seed crystals will produce myriads of tiny copper sulfate
crystals instead of just a few, large crystals. Even the process of pouring the
saturated solution from one container to another can trigger the production of
large numbers of seed crystals. Carefully pouring the solution slowly and
avoiding any splashing will reduce the chance of creating extra seed crystals.
on the right was allowed to evaporate for two weeks and it
produced the following crystals.
a nice cluster of copper sulfate crystals
The deep beautiful blue color makes copper sulfate a popular chemical for
Copper sulfate produces Triclinic crystals.
The triclinic shape of copper sulfate can be seen in this cluster of crystals.
sulfate crystals are somewhat strange. Some crystals can hold their
color for years with no change, while others dehydrate and turn into a white
This crystal of copper sulfate is nearly twenty years old. Note the white
patches where it is starting to dehydrate.
Notice the fingerprints on this crystal of copper sulfate. The crystals that have
been grown at room temperature from solution are water soluble. Moisture from
your fingers can dissolve these crystals and leave finger prints on the crystal
surfaces. So, if you want to keep your specimens shiny, don't touch the crystal
surfaces. The finger prints also indicate that some of the copper sulfate dissolved
and now you have some copper sulfate on your hands.
The attractive specimen above is also nearly twenty years old. It was kept
away from heat and light which is why it did not deteriorate.
sulfate forms naturally, it is known as the mineral chalcanthite.
links on growing copper sulfate crystals
How to Grow Copper Sulfate Crystals
VIDEO: 4 Hour Copper Sulfate Crystals
VIDEO: My Biggest Copper Sulfate Crystal Ever
VIDEO: Copper Sulfate Crystal