How to distinguish flint from chalcedony?

No. 1-174. Moscow region. 14 x 12 x 1 cm

Investment name: Flint (aggregate, mainly chalcedony, opal)

Features

Hardness (Mohs Scale)	6,5-7,0
Density	2,57-2,64
Refraction	1,526-1,544
Birefringence	0,009
Variance	No
Color	Colorless, from milky white to gray, black, blue, yellow, brown. Plain or spotted, striped-zonal throughout the nodule.
Transparency	Translucent to opaque.
Forms of selection	Nodules are a viscous, strong aggregate of cryptocrystalline and amorphous silica.
Syngonia	Absent.
Cleavage	Absent.
Kink	Conchoidal, uneven.
double refraction	White.
Pleochroism	Absent.
Absorption spectrum lines	Not diagnosed.
Luminescence and Chelsea filter	Absent.
Characteristics	A viscous aggregate consisting of chalcedony, quartz and opal. Based on their composition, they are distinguished between cream-chalcedony-quartz, chalcedony and opal-chalcedony. Often you can see a zonal or banded pattern on the surface of the flint. The color is caused by impurities; its intensity and shades can be changed by heat treatment.
Field	Russia (Moscow region, Arkhangelsk region, Leningrad region, Novgorod region, Vladimir region; Ural), Ukraine, USA, etc.
Brilliance	Wax.
fragility	Durable, viscous.

More about flint

Decorative FLINT – a rock, mainly chalcedony Flint is a quartz rock, mainly chalcedony with admixtures of opal, clayey and ferruginous substances. Decorative flints are monolithic fine- and crypto-grained siliceous formations (concretions of round, lamellar, cylindrical and other shapes), monochromatic and variegated. Their hardness is 6-7, the fracture is rough, conchoidal to splintered. Flints are well cut, ground, and polished. The decorative effect of the stone is determined by the color and pattern. The color of flints is quite varied, but usually not bright, although there are exceptions. Color: light gray, black, yellow-brown, red, cherry, brownish-brown, blue. Its intensity and shades can be changed by firing at temperatures from 90 to 350 degrees. Cocentric-zonal flints with a clear pattern and bright color are the most interesting ornamental, and with a fine pattern, jewelry material. Mottled flints are characterized by mottled colors of various tones without a clear pattern – their bulk is unevenly crystallized. Due to the rarity of brightly colored “patterned” varieties, decorative flints did not immediately come into human use as an ornamental stone, in contrast to the widely developed and long-used technical flints. Deposits of decorative flints are known all over the world. They also exist in Russia, from which flints from the Moscow region and the Caucasus can be distinguished by their beauty. Very beautiful flints are found in Ukraine.

Market prices* for inserts, raw materials and collection stones (in USD) (*indicative)

Faceted inserts (per 1 carat)			Gold price ratio
1 carat or less	3-5 carats	10 carats or more
In Russia	virtually absent	virtually absent	virtually absent	——
Abroad	virtually absent	virtually absent	virtually absent	——

For 1 g of raw materials	Crystals	Shufts	Rarely available for sale
In Russia	0,07 – (3) – 8 $/kg	4 – 20 (polished piece)	not presented in specimens	occasionally in products
Abroad	proposed. unknown	proposed. unknown	not presented in specimens	occasionally in products

Chalcedony is a dense cryptocrystalline variety of quartz. It has a fine fibrous structure, visually detectable only under an electron microscope. Chalcedony is characterized by the direction of fiber elongation along one of the L2 axes (110), periodic twisting of fibers around (110), and high twinning density according to the Brazilian law. The fibers are most often collected in dense radial-radiating spherulite bundles, the fusion of which forms kidney-shaped crusts and layers of agates, as well as in parallel-fibrous, cone-shaped, spindle-shaped, scaly, leafy groups. Natural chalcedony is microaggregates of silica, which may contain not only chalcedony fibers, but often also micrograins of quartz itself, zones of quartz and lutecine (moganite), inclusions of cristobalite, tridymite, and opal. The elongation of chalcedony fibers is always perpendicular to the growth surface of its aggregates. The structure of chalcedony contains micropores and microtubules filled with water and/or gas, so when chalcedony is heated to 100° C, it loses somewhat of its original mass. The pores are often filled with other minerals, which, among other things, leads to the formation of the well-known moss agates, which consist of chalcedony with dendrites of impurity minerals (hematite, goethite, celadonite, etc.) grown into its pores. The average pore content in chalcedony is about 2,5% of the total volume, the pore size is about 0,1 microns, and in most cases the variety of its color is associated with them.
The color of chalcedony, as a rule, is secondary and is due to the diffusion penetration of solutions through its pores, depositing pigmenting minerals in them. Thus, the yellow color is associated with microimpurities and inclusions of goethite, and the red color of hematite. Impurities of pyrite, manganese oxides or organic compounds color chalcedony bluish-gray and black. Since the shape and size of the pores vary widely, chalcedony from different deposits is colored differently, the secondary coloring reveals and emphasizes the heterogeneity of the primary structure of the stone. Forms spherulites, spherulitic kidney-shaped crusts, pseudostalactites or solid massive formations. Like quartz, it often replaces other minerals, especially carbonates, forming pseudomorphs. The growth mechanism of chalcedony is not fully understood. • Varieties of chalcedony
Chrysoprase is fine-crystalline silica, consisting of a mixture of chalcedony, quartz, and sometimes moganite and tridymite. As a rule, it is a product of crystallization of colloidal silica or amorphous chrysopal. Colored green with nickel-containing silicates (garnierite, saponite, etc.).
Mtorolite, or chromium chalcedony, is a rare variety of green chalcedony that looks like chrysoprase. Mtorolite, unlike chrysoprase, is colored not by nickel, but by a small amount of chromium in the form of chromium oxide impurities; Unlike chrysoprase, it may also contain small black inclusions of chromite. Green chromium chalcedony was used in jewelry and glyptics during the Roman Empire, and after the discovery of Zimbabwean deposits in 1950, interest in it was renewed. Found in Zimbabwe near the mining town of Mtoroshanga on the Great Dyke. Sapphirine – Sapphirine is colloquially and commercially referred to as chalcedony, colored blue or light milky blue. Translucent samples of rich color are valuable jewelry raw materials. Relatively rare. The color is due to the peculiar dispersion of light. It is necessary to clarify that in mineralogy the name sapphirine refers to a mineral of the silicate class; in relation to bluish chalcedony, this is one example of the incorrect use of a scientific term as a trade brand.
Carnelian – (carnelian, sarder, lincurium, sardonyx) – chalcedony of reddish shades. In sarder and carnelian (old names used since the times of the Ancient World, and now retired from scientific terminology) brown, orange-brown, reddish-brown tones predominate. Carnelian has a dominant yellowish-red, red, and reddish-brown color. The coloring of carnelians is often secondary and is caused by an increased content of ferrous oxide (an admixture of fine hematite). When chalcedony is calcined, the iron it contains changes from the oxide form to the oxide form, which also leads to the appearance of a red-brown color or to an intensification of an existing one. or
Cacholong is a term often used, but not entirely correct due to its vagueness. Usually it is understood as milky-white porcelain-like chalcedony or partially crystallized milky opal. The term can only be used with the obligatory clarification of the composition of the stone: opal cacholong, chalcedony cacholong, quartz cacholong. Or, conversely, in order to emphasize the uncertainty or vagueness of the composition. Cacholongs have structural instability, greater than their own. chalcedony shares of micropores and microimpurities.
Agate is a fine-fibrous aggregate of chalcedony with a concentrically zonal banded texture; the layers are formed by tightly intergrown spherulites. It consists of layers that differ in shade, transparency and density. The composition can be complex; often, along with chalcedony, agate contains layers or ingrowths of other modifications of silica (quartz, quartz, moganite, opal, etc.)
Moss agate or “moss agate” is a gray, bluish, milky-white chalcedony with inclusions of dendrites or osmotic threads of manganese or iron oxides, less commonly celadonite and milky opal, reminiscent of trees, mosses, algae or plant landscapes. The color of these inclusions is varied – black, brown, yellow, red, red, orange-red, green, gray, yellowish-white, etc.
Chalcedony onyx – the name refers to decorative and ornamental stones consisting of chalcedony with parallel straight stripes and layers. Chalcedony onyxes are characterized by parallel-layered alternation of chalcedony itself with layers of quartz and other modifications of silica. Sardonyx is an obsolete term for parallel-banded red chalcedony (carnelian or sarder). It is practically not used in modern scientific literature, but is often found in ancient books about minerals and in art history literature in descriptions of ancient stone products, in particular cameos. Stones of similar texture, composed of calcite, are called marble onyx.
Flint, jasper and heliotrope (or “plasma”) are also often classified as varieties of chalcedony, although this is not entirely true.
These are varieties of natural silica of ambiguous, variable composition, and despite the external resemblance to massive
chalcedony, consist predominantly of fine-grained quartz, which is easily established under a microscope. Although chalcedony fibers, layers or zones are usually also present in them, but in subordinate quantities. It is sometimes very difficult to draw the boundary between agate and jasper, which was pointed out to researchers by A.E. Fersman, who wrote that “the external difference between jasper and agate and chalcedony is really difficult. From a mineralogical point of view, it lies in the predominance of quartz material in jasper, and not . varieties of silica such as chalcedony and quartz (in fact, according to A.A. Godovikov, this is not always exactly the case, because, according to the studies of G.P. Barsanov and M.E. Yakovleva, typical layer jaspers may contain chalcedony, including number and in predominant quantities). In practice, the difference is usually reflected in the degree of transparency at the edges: jaspers are completely opaque or faintly translucent in the fragments; stronger translucency leads to those varieties that are called jasper agate. and, finally, real agates shine through completely.”
Enhydros – translucent concretions of chalcedony, quartz and lutecine, containing residual water. Practical use
Chalcedony is quite beautiful, widespread and relatively cheap. In addition, it easily lends itself to artificial coloring, acquiring any, even very bright, color, but losing the delicate tonality so characteristic of a natural gem. It was quite highly valued in the Ancient World, and the first mentions of chalcedony products are in the Bible. Since ancient times, multi-layered relief artistic images have been carved from parallel-banded sections of agate. In ancient times, chalcedony was used to make festive cups and bowls. Today it is used as an ornamental stone in jewelry and inlays, and “agate” mortars are made from homogeneous chalcedony for grinding hard materials.
Astrology
Modern astrologers attribute chalcedony to the sign of Virgo, while in ancient times it was also considered the stone of Aquarius (Saturn). According to astrological views, chalcedony is especially useful for those born on the 18th and 22nd lunar days. White, pink and blue are favorable for Taurus and Libra, yellow and green are favorable for Virgos, dark varieties are favorable for Capricorns, black chalcedony is a talisman for Scorpios and those born on a full moon. It was also believed that chalcedony patronizes people born under the sign of Sagittarius, gives them self-confidence, childbearing powers, and feeds them with higher cosmic energy.
About the magical healing properties of chalcedony
In appearance, chalcedony is a modest, rather inconspicuous stone, but all varieties of chalcedony and, above all, agate, more than other stones, are shrouded in the fog of healing properties attributed to them.
Some of them came from ancient times, but most of the healing properties of chalcedony were “discovered” in it quite recently, thanks to inventive dreamers today. Alas, with a few exceptions (the effect of flint on water), this stone, like probably any other, does not have any reliably known medical qualities; in any case, they have not been confirmed by serious scientific research. Many common conjectures, which have become the subject of dozens of popular scientific-phantasmagorical books, owe their popularity to the power of suggestion and self-hypnosis, and everyday superstitions against the backdrop of ignorance or fair distrust of people towards the low quality of today’s healthcare.
So what is attributed to this stone, what “miraculous powers” ​​are supposedly contained in it?
The magical properties of chalcedony have been described since ancient times. It was believed that chalcedony carries “the feminine principle, the will to life, love and happiness.” In the countries of the East, amulets were made from it, banishing melancholy and supposedly bringing happiness and joy. Sorcerers made amulets from it that could ward off evil spirits and protect against nightmares. In European countries, magicians used chalcedony to make amulets for sailors.
In modern sources we also find the following:
“Bluish chalcedony calms the nervous system and strengthens memory,” they “increase blood pressure, help normalize cardiac activity, . Chalcedony is useful for nervous exhaustion, it helps fight depression, psychosis, relieves nightmares and insomnia.” Women “to attract love and happiness need to wear a chalcedony bracelet as a talisman; it maintains peace in the family and keeps the spouse from cheating.” Also, “chalcedony in the house protects against natural disasters and neutralizes the influence of geopathogenic zones.” To increase the effect of the talisman, it is advised to “put it under the mattress of the marital bed.” It is stated that “all chalcedony brings calm, sharpens the mind and gives wisdom, relieves outbursts of anger and develops accuracy, and the healing effect can be achieved by contacting the stone with the skin – applying it to a diseased organ or wearing it close to the body; It is most useful to mount a chalcedony disk under the frame of a wristwatch. For respiratory diseases, chalcedony should be worn on a string around the neck. If you have a cold, you should drink chalcedony extract(!) in the evenings.” Also, “for impotence and prostatitis, you should wear the stone on your body in a pocket specially made for it, and for ulcers, gastritis and decreased libido, place it on your navel while lying on your back.” “People sensitive to changes in weather should use chalcedony in combination with rock crystal.” Colored chalcedony is called “stones of love,” claiming that “they attract male attention to a woman, give birth to passion, harmonize sexual life, strengthen men’s erections and encourage them to have offspring.” Chalcedony “is able to drive away melancholy,” and “the energy of chalcedony depends on the brightness and the greater it is, the stronger the stone. ” etc. “Red carnelian promotes the emergence of love in those who wear it, protects against infidelity, is a sure remedy against debauchery and evil passions,” “carnelian promotes conception, strengthens male strength; cleanses the body, promotes concentration and creative activity.” “Wearing a ring with agate can add eloquence and intelligence to a person, ward off a storm, help in sports, pacify anger,” and wearing agate beads or a gold necklace with agate in some cases “increases libido and prolongs pleasure, stimulates female orgasm,” and in others “stimulates spiritual awakening.” We also learn that “chalcedony provides the opportunity to freely express thoughts and feelings, it opens the way to receiving higher energies, and at the right moment suggests the right words,” and that “agate can help in solving dermatological problems, and in case of illnesses, agate should be worn closer to a diseased organ: if the throat or thyroid gland hurts, then agate beads will help, and for toothache and headaches, wearing a stone in earrings is useful.” Esoteric practices of using alcohol and water infusions based on chalcedony and moss agate are especially effective; Thus, an alcohol tincture of bluish chalcedony (sapphirine), prepared during the full moon from May to September, when taken orally three times, 15 drops each, for 2-3 months, gives the body a firm commitment at the cellular level to rejuvenation and serves as an astral stimulus for recovery from many ailments .
Against the background of such a vinaigrette, it is not always easy to distinguish serious astrology from someone’s nonsense and a real parapsychologist from an illiterate swindler. How seriously to take such judgments is a free choice for everyone.