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Acanthite and Argentite are usually grouped together in mineral guides as one mineral...
are usually grouped together in mineral guides as one mineral. However, they are scientifically categorized as two unique minerals, even though they are composed of the same substance. They only differ in
. As explained below, Argentite cannot exist at normal temperatures. Specimens labeled as Argentite are sometimes sold by dealers, however, these specimens are really Acanthite
s after Argentite.
Because Acanthite is a significant
of silver, and occurs in odd and unique forms, its specimens command high prices and are sought after by collectors.
Actinolite and Tremolite are two very similar minerals that form a series with each o...
are two very similar minerals that form a
with each other and essentially share the same
. Actinolite has a greater presence of iron over magnesium, whereas Tremolite has a greater presence of magnesium over iron.
The green color of Actinolite is produced by the iron in its
. The amount of iron varies among specimens, causing different contrasts of green. More iron will give a specimen a darker color.
Actinolite sometimes occurs as thin, splintery
crystals. If the inclusions are parallel and dense, it will cause
in the Quartz.
Actinolite and Tremolite share several recognized varieties.
, a thickly
and leathery variety, has a
, a soft felt-like feel, and
, another fibrous variety, is made up of tough, interlocking fibers, so dense that the fibers are not discernible. Translucent Nephrite with a uniform or interesting color distribution that is extremely tough fits under the category of
Actinolite and Tremolite both contain a form of
which is made of movable and
s. Actinolite asbestos is less common; most forms are in fact Tremolite. This form of the mineral contains significant health hazards and is further discussed in the
mineral detail page.
Adamite occurs in many different lively colors. Different impurities are responsible ...
Adamite occurs in many different lively colors. Different
are responsible for the color types. When copper is present in Adamite, this gives a vibrant green or blue color, and when cobalt is present, it gives a pink to purple color. Some impurities such as copper prevent the Adamite from its habit of being
Adamite crystals are usually embedded in
, crumbly, brown
that stain the hands. Since the Limonite crumbles when scrubbed, care must be exercised when washing such specimens.
Aegirine is a member of the pyroxene group , and forms a series with the mineral Augi...
Aegirine is a member of the
, and forms a
with the mineral
. It is well known for its long slender crystals with very distinctive
s, and some of the more lustrous forms of this mineral are true classics. Aegirine was named by Norweigan
Hans Morten Thrane Esmark (1801–1882). Esmark named this mineral after Aegir, a mythical Norse sea god, in recognition of the discovery of Aegirine near the sea.