The Mineral NEALITE

Chemistry: Pb₄Fe(AsO₄)₂Cl₄ , Lead Iron Arsenate Chloride
Class: Phosphates
Subclass: Arsenates
Uses: Only as mineral specimens.
Specimens

Nealite is a very rare mineral. It was named for an American mineral collector, Neal Yedlin. Nealite is known from one locality, its type locality of Lavrio (formerly Lavrion and Laurium), Greece. Other rare minerals from this locality include paralaurionite, laurionite, ktenasite, zincaluminite, fiedlerite, penfieldite, serpierite, thorikosite, glaucocerinite, beudantite, georgiadesite and phosgenite to name just a few. This locality has been mined for centuries starting with the Greeks and then the Romans for the lead content of its ores. The left over rocks, that were judged too poor in the metals to be processed by the ancient miners, were dumped into the sea. Such mining dumps are called slag dumps. Today these dumps are being reprocessed for their valuable metals by modern ore processing techniques that are capable of extracting the metals from these ores. Analysis of these rocks have yielded some amazing new minerals. Some of these minerals were not there when the rocks were first mined centuries before. But they are there now! The sea water altered the low grade lead ores and produced a most unusual assortment of rare minerals of which nealite is one of them. Many people do not consider these minerals to be true minerals because their creation was indirectly aided by the actions of humans and therefore not exactly natural. Minerals must have a natural origin in order to be minerals. However, these minerals were only indirectly affected and the study of their origins is best left to mineralogists.

Nealite has a bright and attractive color. It is found only in microcrystals and is very hard to obtain for one's collection. But its beauty, rarity and interesting origin make it a very desirable mineral, especially for micromounters.

PHYSICAL CHARACTERISTICS:

Color is typically orange, also yellow.
Luster is vitreous.
Transparency: Crystals are transparent to translucent.
Crystal System is trigonal.
Crystal Habits include platy prismatic to acicular crystals with a sharp domal termination.
Cleavage is absent.
Fracture is uneven.
Hardness is 4
Specific Gravity is approximately 5.88 (well above average for translucent minerals)
Streak is a pale orange yellow.
Other Characteristics: Crystals are brittle.
Associated Minerals include paralaurionite, georgiadesite and other rare lead slag minerals.
Notable Occurrences are limited to the type locality of Lavrio (formerly Lavrion and Laurium), Greece.
Best Field Indicators are color, crystal habit, high density, brittleness and locality.