New Year, New Finds Update 08 January 2021

8 January 2021

Continuing with this week’s theme, New Year, New Finds, we focus entirely on the recent magnificent discovery of Chrysocolla replacing Malachite after Azurite and coated with Quartz from the Tenke-Fungurume area of the Democratic Republic of the Congo (DRC) in Central Africa. This region is famous for its colourful and rare copper minerals and today’s selection is no exception because such pseudomorphs are extremely uncommon.

For anyone unfamiliar with the term pseudomorph, it means “false form” or “false habit” and describes a mineral which, through processes of piecemeal atom substitution, has replaced a pre-existing mineral, but retained the original crystal habit.

The 21 specimens we offer today have undergone this process twice; first Azurite was replaced with Malachite (both copper carbonates) and then at some later stage in geological history, Chrysocolla, a hydrated copper phyllosilicate, has replaced most of the Malachite, only to leave a narrow core remaining within the Chrysocolla crystals.

Such changes take place in the Earth because geological processes never remain static. Water saturated with atomic elements is constantly on the move within the Earth’s crust and it is through changes in temperature, pressure, fluid chemistry, acidity-alkalinity (pH) and oxidation potential (Eh), that pseudomorphing in minerals is driven.

The Chrysocolla is mainly a stunning vivid sky-blue and in most specimens a remnant core of deep leaf or emerald-green Malachite remains. No Azurite remains, but its original presence is known because of the crystal shape of the Chrysocolla, which typically forms elegant gently curving Gothic-style arches, the morphology of the original Azurite.

The specimens are coated in a drusy layer of micro-crystalline Quartz which is transparent and colourless, adding sparkle and intensifying the blue of the Chrysocolla. In addition to the Malachite cores, later-stage Malachite often crystallises in dark green small globular clusters or rosettes on the surface of the Chrysocolla, making magnificent specimens.

Although all today’s specimens are from the same locality and of the same mineralogy, their form varies enormously from single off-matrix crystals to superb hedgehog-like spiky clusters. We hope you enjoy looking through these fascinating new finds from Central Africa and possibly discover for yourself a nice treat to fend-off those January blues!

Here is what you have to look forward to in next week's updates:

Tuesday 12th January and Friday 15th January - Small but beautiful

                                         

Can't find what you're looking for? Contact us at orders@crystalclassics.co.uk for any enquiries.

MINERAL WISH LIST

We also offer an additional service that enables you, as our customer, to contact us via orders@crystalclassics.co.uk with your mineral wish list to enhance your current collection, but are unable to find the right specimens on our website.  We have 1000's of specimens in our general stock that do not appear online.  

We will endeavour to respond to all email/telephone enquires within 24 hours during weekdays, however at the weekend it might take us a little longer to respond.

Author: JH
Categories: Updates

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