The Mines and Minerals of Lavrion - Agardite-(La)Last Updated: 14th Dec 2019
By Branko Rieck
AGARDITE-(La), LaCu6(AsO4)3(OH)6 · 3H2O, hexagonal
Please also note the general remarks here!
Crystals of Agardite-(La) appear as thin hexagonal crystals that are usually found in radial sprays, but occasionally also as randomly scattered on the matrix. Their color ranges from white to blue-green. Color is not a distinguishing feature of agardite-(La) (compare Fig. 1 and Fig. 3)! It can easily be confused with the other minerals of the agardite subgroup, goudeyite and zálesíite. Plumboagardite due to its scarcity and mixite due to its characteristic paragenesis are both less prone to be mixed up with agardite-(La).
Agardite-(La) is quite often the only mineral in vugs in the gossan matrix. If not, Cu-bearing adamite is the most common mineral to accompany it, followed by conichalcite. Malachite and azurite are often seen in the vicinity, too. Quite a bit rarer are associations with other copper-bearing minerals like parnauite, brochantite, rosasite and cornwallite.
Apart from finds at the Kamariza Dump agardite-(La) occurs in larger quantities at the Hilarion and Christiana mines. The most productive places in the Hilarion area are concentrated at the 2nd and 3rd levels, while in the Christiana area the 1st, 2nd and 3rd levels yield great specimen. In the late 1980s the most prominent local collectors at that time – Christos Kapellas and Stathis Lazaridis – either together or individually worked on a large occurrence of agardite-(La) at the 2nd Level of the Christiana area. This find yielded hundreds if not thousands of specimens with agardite subgroup minerals, azurite, brochantite and copper-bearing adamite. In most cases a thin core of the agardite crystals consists of agardite-(Ce), while the rim is composed of agardite-(La) (see Fig. 4).
Fig. 1: The nicest agardite-(La) specimen I have in my collection.
Fig. 2: Typical specimen of agardite-(La) with no other mineral present.
Fig. 3: Ca-bearing agardite-(La) with minor copper-bearing adamite.
Fig. 4: Sprays of agardite-(La) with copper-bearing adamite from the late 1980s find by Christos Kapellas and Stathis Lazaridis.
Thanks go to Dr. Uwe Kolitsch for constructive comments and diligent proofreading to improve this article.
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