THE MINERAL REALGAR

  • Chemistry: AsS, Arsenic Sulfide
  • Class: Sulfides and Sulfosalts
  • Uses: A major ore of arsenic, formerly used for pigments, firework coloring agent and as mineral specimens.
  • Specimens
Realgar is an oddball among the sulfides. It is one of only a few sulfides that are not metallic or opaque or blandly colored. Its structure is analogous to that of sulfur and resembles sulfur in most respects except for color (the name "ruby sulfur" has been applied to realgar). Sulfur has a structure composed of 8 sulfur atoms linked in a ring. Realgar's structure alternates between sulfur atoms and arsenic atoms producing rings of As4S4. The arsenic atoms affect the structure altering it from sulfur's orthorhombic symmetry to realgar's monoclinic symmetry.

Realgar occurs in hydrothermal veins with valuable metal sulfide ores and its bright red color can be an aid to prospectors. It also can be found in hot spring deposits and as a volcanic sublimate product (crystallizing from vapors). Realgar gets its name from the Arabic words for "powder of the mine" (rahj al ghar). Realgar is famous for some wonderfully beautiful specimens. Some specimens can have a deep ruby red color with an amazing clarity and a high luster. The color of realgar is truly something to appreciate and cherish. But realgar's beauty is sometimes fleeting.

It is an unstable mineral and will alter to a different mineral, pararealgar and eventually to a powder. This process takes time and is accelerated by exposure to light. Specimens should be stored in dark, enclosed containers, and only exposed to light for the brief enjoyment of its owner and friends. This sounds extreme, but wonderfully beautiful realgar specimens are worth preserving for as long as possible. If you are wondering how quickly the deterioration occurs, the answer is immediately, but fortunately very slowly. Ancient Chinese carvings of realgar are still in existence, but badly affected by the deterioration. The deterioration of realgar was thought to produce the closely related yellow orpiment, but this was recently proven to be false and the deterioration product is in fact yellow-orange pararealgar. In old paintings and manuscripts, realgar was a common pigment for paints and dyes. Many of these paintings now have a yellow or orange hue where once the color must have been an original red.

PHYSICAL CHARACTERISTICS:

  • Color is orange to red.
  • Luster is resinous, adamantine to sub-metallic.
  • Transparency: Crystals are translucent to transparent.
  • Crystal System: Monoclinic; 2/m.
  • Crystal Habits: include prismatic striated crystals with a rounded diamond-like cross-section. They are terminated by a wedge-like dome. Also found as grains, crusts and earthy masses.
  • Cleavage is good in one direction.
  • Fracture is subconchoidal.
  • Hardness is 1.5 - 2
  • Specific Gravity is 3.5 - 3.6
  • Streak is orange to orange-yellow.
  • Other Characteristics: Realgar is unstable in light; specimens should be stored in complete darkness, rarely some specimens fluoresce under UV light and crystals are pleochroic between dark red and orange red.
  • Associated Minerals almost always include orpiment, also calcite, stibnite and other metal sulfide ores.
  • Notable Occurrences include most importantly Hunan Province, China; but also Switzerland; Japan; Macedonia; Mercur, Utah, USA; Romania and many other localities.
  • Best Field Indicators are of course color as well as crystal habit, association with orpiment, softness and luster.
REALGAR specimens:
(hover for more info)
REALGAR specimen rea-1
$ 45.00
Dims: 2" x 1-5/8" x 2-1/8"
Wt: 6.1 oz. w/ base
China Realgar Mine, Hunan Province, China
Though this specimen closey resembles Crocoite, one whiff will tell you the difference; Realgar has a noticeable garlic/sulfur odor. The intense red of this specimen is caused by a tightly-packed cluster of crystals that reach almost 1/4 long. This isone of the best examples of Realgar that I've seen; you should consider it if you're looking for one.
no photo
rea-1 ($ 45.00)
China Realgar Mine, Hunan Province, China
REALGAR specimen rea-2
$ 60.00
Dims: 3" x 2-1/4" x 1-1/8"
Wt: 3.6 oz
Shimen County, Hunan Province, China
Exceptional color and clarity mark this specimen as an example of Chinese Realgar. The crystals, when complete, are well-terminated and a deep-red color, containing internal fractures and flaws that one must look for to see. Along with the Realgar are several good-quality crystals of Calcite, including one base-to-base contact twin that makes a lovely scalenohedron! There are also tiny clusters of fibrous, radiating white crystals that I cannot identify! Somebody help!
no photo
rea-2 ($ 60.00)
Shimen County, Hunan Province, China
REALGAR specimen rea-3
$ 30.00
Dims: 1/2" x 1/2" x 1/4"
Wt: 3 g
Hunan Realgar Mine, Hunan Province, China
Though not complete, this is a gorgeous little thumbnail specimen of Realgar, and would be easily gem-quality if such a mineral could be cut into gems. The crystals are well-terminated, a deep red in color, and remarkably clear. There is no matrix, only Realgar. This is absolutely a thing of beauty!
no photo
rea-3 ($ 30.00)
Hunan Realgar Mine, Hunan Province, China
REALGAR specimen rea-5
$ 135.00
Dims: 2-3/4" x 1-1/8" x 3/4"
Wt: 1.25 oz
Shi Meng Mine, Shi Meng, Hunan Province, China
I like this Realgar specimen best of all because of its simplicity. There is not a confusing cluster of crystals, and everything is easy to see on it. That is because the specimen basically consists of one large crystal of Realgar that has a broken section of another crystal coming off of it at its base. The complete crystal measures 2-3/4" x 1" x 3/8", and is almost completely free from damage. The crystal, aside from substantial internal fracturing, is transparent, and has the deep red color that is associated with this mineral.
no photo
rea-5 ($135.00)
Shi Meng Mine, Shi Meng, Hunan Province, China
REALGAR specimen rea-6
$ 150.00
Dims: 2-1/2" x 1-7/8" x 7/8"
Wt: 1.83 oz
Shi Meng Mine, Shi Meng, Hunan Province, China
There are over a dozen deep red Realgar crystals on the matrix of this specimen, amid several partials. Some of the complete crystals have some damage, a few have considerable damage, but the majority are in very good condition. They all have Realgar's classic deep red color, transparency, and prismatic crystal form. The largest crystal measures about 3/4" x 5/8" x 3/16". This is a very beautiful mineral, and here we have several crystals on a really nice specimen.
no photo
rea-6 ($150.00)
Shi Meng Mine, Shi Meng, Hunan Province, China
REALGAR specimen rea-7
$ 35.00
Dims: 2.5" x 1.6" x 1.1" (6.4 x 4.1 x 2.8 cm)
Wt: 1.97 oz. (55.8 g)
Hunan Province, China
At least 10 small but complete crystals are gathered in a cluster on this specimen they do not exceed 0.6" (1.5 cm) in length, but have good crystal form and only small amounts of damage. All have Realgar's characteristic crimson-red color and a submetallic luster. They show excellent translucence with small spots of transparence. These Realgar crystals are gathered around one side of a scalenohedral "dogtooth" calcite crystal that shows no damage, a pale cream coloration, and faint transparence. It is adjacent to another calcite that is broken and incomplete. Small clusters of tiny acicular, radiating white needle-like crystals are scattered about the specimen. I do not know what mineral they are composed of, as yet. It is a beautiful specimen.
no photo
rea-7 ($ 35.00)
Hunan Province, China
REALGAR specimen rea-8
$ 55.00
Dims: 3.0" x 2.6" x 1.9" (7.6 x 6.6 x 4.8 cm)
Wt: 7.09 oz. (201.0 g)
Hunan Province, China
This specimen is rather interesting. I am having difficulty finding a single complete, undamaged Realgar crystal on it. However, there is a lot of material to look over! Over 80% of its mass is made up of bright red intergrown Realgar crystals. Though damage is pervasive, crystal form is well-defined, and there are alternately many intact prisms and terminations, it is simply that few are found together on one crystal. The Realgar has the obligatory bright red color, a pearly to vitreous luster, and is translucent, with slight transparence in areas. Attached to this intergrown confusion is a small amount of crystalline calcite with a few small clusters of acicular, radiating white needles that I cannot identify. It is one of our more "Realgar-rich" specimens.
no photo
rea-8 ($ 55.00)
Hunan Province, China
REALGAR specimen rea-9
$ 45.00
Dims: 3.1" x 2.6" x 1.6" (7.9 x 6.6 x 4.1 cm)
Wt: 4.27 oz. (121.1 g)
Hunan Province, China
At least 10 complete, intact Realgar crystals are clustered amid a mass of damaged and broken ones on this specimen. They range from a few millimeters to 0.5" (1.3 cm) in length and have excellent prismatic crystal form with sloping terminations. All have the standard bright red color and a pearly to vitreous luster, with dim transparence in some crystals and translucence in others. They rest on what appears to be a rough gray limestone host rock that has a few well-formed calcite crystals growing out of it. The largest of these calcites measures 1.6" (4.1 cm) long, and all have a pale, creamy color and are dimly transparent.
no photo
rea-9 ($ 45.00)
Hunan Province, China
REALGAR specimen rea-10
$ 40.00
Dims: 1.6" x 1.0" x 0.7" (4.1 x 2.5 x 1.8 cm)
Wt: 18.9 g
Shi Meng Mine, Shi Meng County, Hunan Province, China
Though this specimen is made up of six discernable Realgar crystals, the largest of them is by far the most noticeable, as all the rest are intergrown with and partially enveloped by it. This crystal measures 1.0 x 0.9 x 0.4" (2.5 x 2.3 x 1.0 cm) and though there is some considerable damage in one area of the monoclinic prism, it is in good condition with a complete and well-developed termination that appears to show some partial healing. It has the standard bright-red coloration and vitreous luster of Realgar, and is transparent, though clarity is mostly spoiled due to heavy internal fractures. The smaller crystals are much smaller than this one and are mostly intergrown with it; some show substantial damage. There is a small amount of host rock attached to the large crystal's base.
no photo
rea-10 ($ 40.00)
Shi Meng Mine, Shi Meng County, Hunan Province, China
REALGAR specimen rea-11
$ 110.00
Dims: 1.9" x 1.3" x 1.2" (4.8 x 3.3 x 3.0 cm)
Wt: 1.61 oz. (45.7 g)
Shi Meng Mine, Shi Meng County, Hunan Province, China
At least 6 crystals are intergrown on this specimen. Though there is some noticeable damage, all are in very good condition, with very good monoclinic form and even a few double-terminated crystals. The largest crystal in the cluster has dimensions of 1.8 x 0.9 x 0.6" (4.6 x 2.3 x 1.5 cm), and the next largest measures slightly more than half of those dimensions. All of the crystals have a bright red coloration and a vitreous luster. They all are transparent, too, though heavy internal fracturing destroys their clarity. There is only a tiny spot of host rock attached to the cluster, right next to a double-terminated calcite crystal that appears to be in a very stubby scalenohedral form. It is a beautiful specimen.
no photo
rea-11 ($110.00)
Shi Meng Mine, Shi Meng County, Hunan Province, China
REALGAR specimen rea-12
$ 175.00
Dims: 1.9" x 1.7" x 1.5" (4.8 x 4.3 x 3.8 cm)
Wt: 2.08 oz. (59.2 g)
Shi Meng Mine, Shi Meng County, Hunan Province, China
There are at least 9 different Realgar crystals on the gray limestone host rock of this specimen, but three of them are by far larger and more noticeable than the others. The largest of these has dimensions of 1.2 x 1.0 x 0.5" (3.0 x 2.5 x 1.3 cm), and the others are about one-fourth that size. All have good monoclinic form, though the two smaller crystals are rather intergrown. They have a bright, vitreous luster and show dim transparence in some areas. Accompanying the Realgars is a cluster of small, gray-white dogtooth calcites. Their form is excellent, they show almost no damage, and they do not exceed 0.5" in length. All are transparent to a degree, and the largest has a subtle phantom visible inside. There is also a patch of puffy, round clusters of white acicular, radiating needles on the specimen's underside- I have no idea what these are made of.
no photo
rea-12 ($175.00)
Shi Meng Mine, Shi Meng County, Hunan Province, China
REALGAR specimen rea-13
$ 300.00
Dims: 2.0" x 1.7" x 1.0" (5.1 x 4.3 x 2.5 cm)
Wt: 2.42 oz. (68.6 g)
Shi Meng Mine, Shi Meng County, Hunan Province, China
At least 20 different crystals are clustered together in this specimen; there are probably many more than that, but most of them are so intergrown that they could be collectively regarded as a few, larger crystals. As it is, at least 5 crystals make up the bulk of the piece, reaching dimensions of up to 2.0 x 1.0 x 0.4" (5.1 x 2.5 x 1.0 cm). Many smaller crystals partly protrude from these larger ones, including some very tiny ones whose visible dimensions do not exceed 2 mm. Their intense intergrowth makes it difficult for one to effectively isolate individual crystals and determine their monoclinic bladed/prismatic form, but a few small ones show some individuality. The larger intergrown "associations" show definite wedge-shaped terminations, and could, in effect, be called "double-terminated". All have the deep, crimson-red coloration that is the hallmark of this mineral, and their bright, nearly adamantine luster is pervasive. Again, their intergrowth makes it difficult for one to determine their clarity, but most of the crystals are definitely transparent. There is no host rock or other material on the specimen.
no photo
rea-13 ($300.00)
Shi Meng Mine, Shi Meng County, Hunan Province, China
REALGAR specimen rea-14
$ 300.00
Dims: 3.8 x 3.6 x 1.6" (9.7 x 9.1 x 4.1 cm)
Wt: 8.4 oz. (236.7 g)
Shi Meng Mine, Shi Meng County, Hunan Province, China
This hand specimen consists of a dull gray, weathered base rock upon which rest at least 30 Realgar crystals. These crystals range in length from less than 0.1" (3 mm) to over 1" (2.5 cm). About half of them are damaged or broken, but those that are intact have excellent monoclinic prismatic form, with well-defined edges and clean faces that possess a bright subadamantine luster. All have the classic crimson-red coloration that is the primary characteristic of this mineral, and are dimly to moderately transparent, containing substantial internal fractures. Among the Realgar crystals are several warped calcite crytals that are mostly obscured by the Realgar, and many tiny clusters of white, radiating needles- I do not know of what mineral they are made.
no photo
rea-14 ($300.00)
Shi Meng Mine, Shi Meng County, Hunan Province, China
REALGAR specimen rea-15
$ 120.00
Dims: 1.9 x 1.9 x 1.1" (4.9 x 4.8 x 2.7 cm)
Wt: 2.69 oz. (76.2 g)
Shi Meng Mine, Shi Meng, Hunan Province, China
This hand specimen consists of a cluster of partly intergrown Realgar crystals. Most of the crystals are moderately to heavily damaged, but a few are intact and very good condition. The largest of them has visible dimensions of 1.4 x 1.3 x 0.7" (3.6 x 3.4 x 1.7 cm). All have very good monoclinic form where intact, with a pearly-to-vitreous luster. All have the classic crimson color and are transparent but contain many internal fractures. Only a small smattering of a dark gray base rock is present.
no photo
rea-15 ($120.00)
Shi Meng Mine, Shi Meng, Hunan Province, China
REALGAR specimen rea-17
$ 63.00
Dims: 2.48x1.57x1.18" (6.3x4.0x3.0cm)
Wt: 1.74oz. (49.2g)
?
This small hand specimen of realgar has some excellent crystals. The color is dark red, and (especially under a loupe) the crystals are transparent and have a high luster. While most of the crystals are damaged or incomplete, there are a number of small perfect crystals, and a large crystal is contained within a protective cavity and is excellent, although largely buried. All of the cavities of the host rock contain nice realgar crystals. The bottom of the specimen has additional minerals visible, and the most noteworthy example is a black mineral which otherwise looks like realgar, and indeed some crystals appear to shade from realgar red on one end to black on the other (but I have never heard of a black realgar).
no photo
rea-17 ($ 63.00)
?
REALGAR specimen rea-16
$ 75.00
Dims: 2.60x2.09x1.42" (6.6x5.3x3.6cm)
Wt: 5.43oz (153.6g)
Getchell Mine, South Pit, Potosi District, Humbolt County, Nevada, USA
A black, porous rock is host to some crusts and crystals of realgar. Along one ridge of this rock, the crystals are essentially transparent, and have excellent form and a dark red color. but those are relatively small crystals. Along one side of the rock, the realgar crystals are quite a bit larger (upp to 15mm long), but these crystals are dull and nearly opaque. However, one of them is well formed, and is adjacent to an interesting spray of an unidentified white mineral, which presents as an upside down radial cluster of blades. The crystals are clean and well-formed, and I think I should be able to identify it, but I have not, yet. It looks like a white, crystalline starfish perched just past that large realgar crystal.
no photo
rea-16 ($ 75.00)
Getchell Mine, South Pit, Potosi District, Humbolt County, Nevada, USA
REALGAR specimen rea-18
$ 45.00
Dims: 1.89x1.48x0.95" (4.81x3.76x2.41cm)
Wt: 1.08oz (30.6g)
Getchell Mine, South Pit, Potosi District, Humbolt County, Nevada, USA
A black micro-crystalline rock hosts several nice transparent deep red realgar crystals, plus several thin orange crusts. It may be that only the surface is orange and translucent, as a loupe shows that this crust still has crystal form with hints of red transparency. The largest crystals measure more than 14mm long, and are clean and striated, although most of the terminations are missing.
no photo
rea-18 ($ 45.00)
Getchell Mine, South Pit, Potosi District, Humbolt County, Nevada, USA
REALGAR specimen rea-19
$ 28.00
Dims: 2.04x1.51x1.47" (5.19x3.83x3.74cm)
Wt: 3.92oz (110.8g)
Alsitar, Iran
This specimen may be mostly realgar by weight. It is composed of crystals of transparent red realgar intergrown with some black mineral that looks vitreous, possibly even transparent in areas. The realgar has begun to alter to orange-red, powdery para-realgar in several places. To retard that inevitable process, realgar specimens should be stored in the dark and only exposed to light when they are being actively examined.
no photo
rea-19 ($ 28.00)
Alsitar, Iran
 

Copyright ©1995-2023 by Amethyst Galleries, Inc.