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Gemstone: For other uses, see Gemstone (disambiguation), Gem (disambiguation), Gems (disambiguation), Jewels (disambiguation) and Precious Stone (disambiguation). Group of precious and semiprecious stones—both uncut and faceted—including (clockwise from top left) diamond, uncut synthetic sapphire, ruby, uncut emerald, and amethyst crystal cluster.

A gemstone (also called a gem, fine gem, jewel, precious stone, or semi-precious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli and opal) and occasionally organic materials that are not minerals (such as amber, jet, and pearl) are also used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity is another characteristic that lends value to a gemstone.

Apart from jewelry, from earliest antiquity engraved gems and hardstone carvings, such as cups, were major luxury art forms. A gem maker is called a lapidary or gemcutter; a diamond cutter is called a diamantaire.

Contents: 1.Characteristics and classification, 2.Value, 3.Grading, 4.Cutting and polishing, 5.Colors, 6.Treatment, 6.1. Heat, 6.2. Radiation, 6.3. Waxing/oiling, 6.4. Fracture filling, 7. Synthetic and artificial gemstones, 8.List of rare gemstones, 9.See also,10. References,11. External links

Characteristics and classification

A collection of gemstone pebbles made by tumbling the rough stones, except the ruby and tourmaline, with abrasive grit inside a rotating barrel. The largest pebble here is 40 mm (1.6 in) long.

The traditional classification in the West, which goes back to the ancient Greeks, begins with a distinction between precious and semi-precious; similar distinctions are made in other cultures. In modern use the precious stones are diamond, ruby, sapphire and emerald, with all other gemstones being semi-precious. This distinction reflects the rarity of the respective stones in ancient times, as well as their quality: all are translucent with fine color in their purest forms, except for the colorless diamond, and very hard, with hardnesses of 8 to 10 on the Mohs scale. Other stones are classified by their color, translucency, and hardness. The traditional distinction does not necessarily reflect modern values, for example, while garnets are relatively inexpensive, a green garnet called tsavorite can be far more valuable than a mid-quality emerald. Another unscientific term for semi-precious gemstones used in art history and archaeology is hardstone. Use of the terms 'precious' and 'semi-precious' in a commercial context is, arguably, misleading in that it deceptively implies certain stones are intrinsically more valuable than others, which is not necessarily the case.

In modern times gemstones are identified by gemologists, who describe gems and their characteristics using technical terminology specific to the field of gemology. The first characteristic a gemologist uses to identify a gemstone is its chemical composition. For example, diamonds are made of carbon (C) and rubies of aluminium oxide (Al 2O3). Many gems are crystals which are classified by their crystal system such as cubic or trigonal or monoclinic. Another term used is habit, the form the gem is usually found in. For example, diamonds, which have a cubic crystal system, are often found as octahedrons.

Gemstones are classified into different groups, species, and varieties. For example, ruby is the red variety of the species corundum, while any other color of corundum is considered sapphire. Other examples are the emerald (green), aquamarine (blue), red beryl (red), goshenite (colorless), heliodor (yellow) and morganite (pink), which are all varieties of the mineral species beryl.

Gems are characterized in terms of refractive index, dispersion, specific gravity, hardness, cleavage, fracture and luster. They may exhibit pleochroism or double refraction. They may have luminescence and a distinctive absorption spectrum.

Material or flaws within a stone may be present as inclusions.

Gemstones may also be classified in terms of their "water". This is a recognized grading of the gem's luster, transparency, or "brilliance". Very transparent gems are considered "first water", while "second" or "third water" gems are those of a lesser transparency.

Value

Spanish emerald and gold pendant at Victoria and Albert Museum

Enamelled gold, amethyst, and pearl pendant, about 1880, Pasquale Novissimo (1844–1914), V&A Museum number M.36-1928

Gemstones have no universally accepted grading system. Diamonds are graded using a system developed by the Gemological Institute of America (GIA) in the early 1950s. Historically, all gemstones were graded using the naked eye. The GIA system included a major innovation: the introduction of 10x magnification as the standard for grading clarity. Other gemstones are still graded using the naked eye (assuming 20/20 vision).

A mnemonic device, the "four Cs" (color, cut, clarity, and carats), has been introduced to help describe the factors used to grade a diamond. With modification, these categories can be useful in understanding the grading of all gemstones. The four criteria carry different weights depending upon whether they are applied to colored gemstones or to colorless diamonds. In diamonds, the cut is the primary determinant of value, followed by clarity and color. The ideal cut diamond will sparkle, to break down light into its constituent rainbow colors (dispersion), chop it up into bright little pieces (scintillation), and deliver it to the eye (brilliance). In its rough crystalline form, a diamond will do none of these things; it requires proper fashioning and this is called "cut". In gemstones that have color, including colored diamonds, the purity, and beauty of that color is the primary determinant of quality.

Physical characteristics that make a colored stone valuable are color, clarity to a lesser extent (emeralds will always have a number of inclusions), cut, unusual optical phenomena within the stone such as color zoning (the uneven distribution of coloring within a gem) and asteria (star effects). Ancient Greeks, for example, greatly valued asteria gemstones, which they regarded as powerful love charms, and Helen of Troy was supposed to have worn star-corundum.

Aside from the diamond, ruby, sapphire, and emerald, the pearl (not, strictly speaking, a gemstone) and opal have also been considered to be precious. Up to the discoveries of bulk amethyst in Brazil in the 19th century, amethyst was considered a "precious stone" as well, going back to ancient Greece. Even in the last century certain stones such as aquamarine, peridot and cat's eye (cymophane) have been popular and hence been regarded as precious.

Today the gemstone trade no longer makes such a distinction. Many gemstones are used in even the most expensive jewelry, depending on the brand-name of the designer, fashion trends, market supply, treatments, etc. Nevertheless, diamonds, rubies, sapphires, and emeralds still have a reputation that exceeds those of other gemstones.

Rare or unusual gemstones, generally understood to include those gemstones which occur so infrequently in gem quality that they are scarcely known except to connoisseurs, include andalusite, axinite, cassiterite, clinohumite and red beryl.

Gemstone pricing and value are governed by factors and characteristics in the quality of the stone. These characteristics include clarity, rarity, freedom from defects, the beauty of the stone, as well as the demand for such stones. There are different pricing influencers for both colored gemstones, and for diamonds. The pricing on colored stones is determined by market supply-and-demand, but diamonds are more intricate.[citation needed] Diamond value can change based on location, time, and on the evaluations of diamond vendors.

Proponents of energy medicine also value gemstones on the basis of alleged healing powers.

Cutting and polishing

A few gemstones are used as gems in the crystal or other forms in which they are found. Most, however, are cut and polished for usage as jewelry. The two main classifications are stones cut as smooth, dome-shaped stones called cabochons, and stones which are cut with a faceting machine by polishing small flat windows called facets at regular intervals at exact angles.

Stones which are opaque or semi-opaque such as opal, turquoise, variscite, etc. are commonly cut as cabochons. These gems are designed to show the stone's color or surface properties as in opal and star sapphires. Grinding wheels and polishing agents are used to grind, shape and polish the smooth dome shape of the stones.

Gems that are transparent are normally faceted, a method that shows the optical properties of the stone's interior to its best advantage by maximizing reflected light which is perceived by the viewer as sparkle. There are many commonly used shapes for faceted stones. The facets must be cut at the proper angles, which varies depending on the optical properties of the gem. If the angles are too steep or too shallow, the light will pass through and not be reflected back toward the viewer. The faceting machine is used to hold the stone onto a flat lap for cutting and polishing the flat facets. Rarely, some cutters use special curved laps to cut and polish curved facets.

Colors

Nearly 300 variations of diamond color exhibited at the Aurora display at the Natural History Museum in London.

A variety of semiprecious stones

The color of any material is due to the nature of light itself. Daylight, often called white light, is all of the colors of the spectrum combined. When light strikes a material, most of the light is absorbed while a smaller amount of a particular frequency or wavelength is reflected. The part that is reflected reaches the eye as the perceived color. A ruby appears red because it absorbs all the other colors of white light while reflecting the red.

A material which is mostly the same can exhibit different colors. For example, ruby and sapphire have the same primary chemical composition (both are corundum) but exhibit different colors because of impurities. Even the same named gemstone can occur in many different colors: sapphires show different shades of blue and pink and "fancy sapphires" exhibit a whole range of other colors from yellow to orange-pink, the latter called "padparadscha sapphire".

This difference in color is based on the atomic structure of the stone. Although the different stones formally have the same chemical composition and structure, they are not exactly the same. Every now and then an atom is replaced by a completely different atom, sometimes as few as one in a million atoms. These so-called impurities are sufficient to absorb certain colors and leave the other colors unaffected.

For example, beryl, which is colorless in its pure mineral form, becomes emerald with chromium impurities. If manganese is added instead of chromium, beryl becomes pink morganite. With iron, it becomes aquamarine.

Some gemstone treatments make use of the fact that these impurities can be "manipulated", thus changing the color of the gem.

Treatment

Gemstones are often treated to enhance the color or clarity of the stone. Depending on the type and extent of treatment, they can affect the value of the stone. Some treatments are used widely because the resulting gem is stable, while others are not accepted most commonly because the gem color is unstable and may revert to the original tone.

Heat

Heat can either improve or spoil gemstone color or clarity. The heating process has been well known to gem miners and cutters for centuries, and in many stone types heating is a common practice. Most citrine is made by heating amethyst, and partial heating with a strong gradient results in "ametrine" – a stone partly amethyst and partly citrine. Aquamarine is often heated to remove yellow tones, or to change green colors into the more desirable blue, or enhance its existing blue color to a deeper blue.

Nearly all tanzanite is heated at low temperatures to remove brown undertones and give a more desirable blue / purple color. A considerable portion of all sapphire and ruby is treated with a variety of heat treatments to improve both color and clarity.

When jewelry containing diamonds is heated (for repairs) the diamond should be protected with boric acid; otherwise, the diamond (which is pure carbon) could be burned on the surface or even burned completely up. When jewelry containing sapphires or rubies is heated, those stones should not be coated with boracic acid (which can etch the surface) or any other substance. They do not have to be protected from burning, like a diamond (although the stones do need to be protected from heat stress fracture by immersing the part of the jewelry with stones in the water when metal parts are heated).

Radiation

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Virtually all blue topaz, both the lighter and the darker blue shades such as "London" blue, has been irradiated to change the color from white to blue. Most greened quartz (Oro Verde) is also irradiated to achieve the yellow-green color. Diamonds are irradiated to produce fancy-color diamonds (which can occur naturally, though rarely in gem quality).

Waxing/oiling

Emeralds containing natural fissures are sometimes filled with wax or oil to disguise them. This wax or oil is also colored to make the emerald appear of better color as well as clarity. Turquoise is also commonly treated in a similar manner.

Fracture filling

Fracture filling has been in use with different gemstones such as diamonds, emeralds, and sapphires. In 2006 "glass-filled rubies" received publicity. Rubies over 10 carats (2 g) with large fractures were filled with lead glass, thus dramatically improving the appearance (of larger rubies in particular). Such treatments are fairly easy to detect.

List of rare gemstones

Painite was discovered in 1956 in Ohngaing in Myanmar. The mineral was named in honor of the British gemologist Arthur Charles Davy Pain. In 2005, painite was described by the Guinness Book of World Records as the rarest gem mineral on earth.

Symbolism of precious stones:

JASPER: The jasper, which like the emerald is of a greenish hue, probably signifies St. Peter, chief of the apostles, as one who so bore Christ’s death in his inmost nature that his love for Him was always vigorous and fresh. By his fervent faith he has become our shepherd and leader.

SAPPHIRE: As the sapphire is likened to the heavens (from this stone is made a color popularly called lazur), I conceive it to mean St. Paul, since he was caught up to the third heaven, where his soul was firmly fixed. Thither he seeks to draw all those who may be obedient to him.

CHALCEDONY: The chalcedony was not inserted in the high-priest’s breastplate, but instead the carbuncle, of which no mention is made here. It may well be, however, that the author designated the carbuncle by the name chalcedony. Andrew, then, can be likened to the carbuncle, since he was splendidly illumined by the fire of the Spirit.

EMERALD: The emerald, which is of a green color, is nourished with oil, that its transparency and beauty may not change; we conceive this stone to signify John the Evangelist. He, indeed, soothed the souls dejected by sin with a divine oil, and by the grace of his excellent doctrine lends constant strength to our faith.

SARDONYX: By the sardonyx, showing with a certain transparency and purity the color of the human nail, we believe that James is denoted, seeing that he bore death for Christ before all others. This the nail by its color indicates, for it may be cut off without any sensible pain.

SARDIUS (red carneole): The sardius with its tawny and translucent coloring suggests fire, and it possesses the virtue of healing tumors and wounds inflicted by iron; hence I consider that it designates the beauty of virtue characterizing the apostle Philip, for his virtue, animated by the fire of the Holy Spirit, cured the soul of the wounds inflicted by the wiles of the devil, and revived it.

CHRYSOLITE: The chrysolite, gleaming with the splendor of gold, may symbolize Bartholomew, since he was illustrious for his divine preaching and his store of virtues.

BERYL: The beryl, imitating the colors of the sea and of the air, and not unlike the jacinth, seems to suggest the admirable Thomas, especially as he made a long journey by sea, and even reached the Indies, sent by God to preach salvation to the peoples of that region.

TOPAZ: The topaz, which is of a ruddy color, resembling somewhat the carbuncle, stops the discharge of the milky fluid with which those having eye-disease suffer. This seems to denote Matthew, for he was animated by a divine zeal, and, his blood being fired because of Christ, he was found worthy to enlighten by his Gospel those whose heart was blinded, that they might like new-born children drink of the milk of the faith.

CHRYSOPRASE: The chrysoprase, more brightly tinged with a golden hue than gold itself, symbolizes St. Thaddæus; the gold (chrysos) symbolizing the kingdom of Christ, and the prassius, Christ’s death, both of which he preached to Abgar, King of Edessa.

JACINTH: The jacinth, which is of a celestial hue, signifies Simon Zelotes, zealous for the gifts and grace of Christ and endowed with a celestial prudence.

AMETHYST: By the amethyst, which shows to the onlooker a fiery aspect, is signified Matthias, who in the gift of tongues was so filled with celestial fire and with fervent zeal to serve and please God, who had chosen him, that he was found worthy to take the place of the apostate Judas.

Some theologians were opposed to the assignment of the foundation stones to the apostles, for they held that only Christ himself could be regarded as the foundation of his Church. Hence the symbolism of these stones was made to apply to Christ alone, the color of the stone often guiding the commentator in his choice of ideas denoted by the different gems. Thus, one writer, applying all the meanings to Christ, finds that the greenish Jasper denotes satisfaction; the sky-blue Sapphire, the soul; the bright-red Chalcedony, zeal for truth; the transparent green Emerald, kindness and goodness; the nail-colored Sardonyx, the strength of spiritual life; the red Sardius, readiness to shed His blood for the Church; the yellow Chrysolite, the excellence of His divine nature; the sea-green Beryl, moderation and the control of the passions; the glass-green Topaz (chrysolite?), uprightness; the harsh-colored Chrysoprase, sternness towards sinners; the violet or purple Jacinth, royal dignity, and, lastly, the purple Amethyst, with a touch of red, perfection.

Symbolism of precious stones connected to tribes and zodiak according to the Jews of medieval times

Andreas of Cæsarea freely recognizes his indebtedness to the much more ancient source, St. Epiphanius, bishop of Constantia in Cyprus, who died in 402 a.d., and who wrote a short but very valuable treatise on the stones of the breastplate, noting in several cases the therapeutic and talismanic virtues of these stones and giving his opinion as to the order in which the names of the tribes were inscribed upon them. As the foundation stones of Revelation are rightly called “apostolic stones,” so those of the breastplate merit the designation of “tribal stones,” as well as that of astral stones; indeed, the Jews of medieval times definitely associated the tribes with the zodiacal signs in the following order:

Judah – Aries, Issachar – Taurus, Zebulun – Gemini, Reuben – Cancer, Simeon – Leo, Gad – Virgo, Ephraim – Libra
Manasseh – Scorpio, Benjamin – Sagittarius, Dan – Capricorn, Naphtali – Aquarius, Asher – Pisces

For Rabanus Maurus the nine gems of the king of Tyre named in Ezekiel xxxviii, 13, are types of the nine orders of angels, just as the twelve foundation stones of Revelation signify the twelve apostles.

It is evident, from early and later usage, that, at the place and time where and when these stones were first utilized for birth-stones, the year must have begun with the month of March. This will be apparent when we compare the following eight lists, carefully gathered from various sources:

The table:

Gems of Spring

Amethyst, Green diamond, Chrysoberyl, Spinel (rubicelle), Pink topaz, Olivine (peridot), Emerald, Gems of Summer, Zircon, Garnet (demantoid and ouvarite), Chrysoberyl (alexandrite). Spinel, Pink topaz, Ruby, Fire opal, Gems of Autumn, Hyacinth, Topaz, Sapphire, Jacinth, Cairngorm, Adamantine spar, Tourmaline, Oriental chrysolite.

GEMS OF WINTER: Diamond, Rock-crystal, White sapphire, Turquoise, Quartz, Moonstone, Pearl, Labradorite

SENTIMENTS OF THE MONTHS

JANUARY: Natal stone Garnet. Guardian angel Gabriel. His talismanic gem Onyx. Special apostle Simon Peter. His gem Jasper. Zodiacal sign Aquarius. Flower Snowdrop.

FEBRUARY: Natal stone Amethyst. Guardian angel Barchiel. His talismanic gem Jasper. Special apostle Andrew. His gem Carbuncle. Zodiacal sign Pisces. Flower Primrose.

MARCH: Natal stone Jasper, bloodstone. Guardian Angel Malchediel. His talismanic gem Ruby. Special apostles James and John. Their gem Emerald. Zodiacal sign Aries. Flower Ipomœa, violet.

APRIL: Natal stone Diamond, sapphire. Guardian angel Ashmodei. His talismanic gem Topaz. Special apostle Philip. His gem Carnelian. Zodiacal sign Taurus. Flower Daisy.

MAY: Natal stone Emerald. Guardian angel Amriel. His talismanic gem Carbuncle. Special apostle Bartholomew. His gem Chrysolite. Zodiacal sign Gemini. Flower Hawthorn.

JUNE: Natal stone Agate. Guardian angel Muriel. His talismanic gem Emerald. Special apostle Thomas. His gem Beryl. Zodiacal sign Cancer. Flower Honeysuckle.

JULY: Natal stone Turquoise. Guardian angel Verchiel. His talismanic gem Sapphire. Special apostle Matthew. His gem Topaz. Zodiacal sign Leo. Flower Water-lily.

AUGUST: Natal stone Carnelian. Guardian angel Hamatiel. His talismanic gem Diamond. Special apostle James, the son of Alpheus. His gem Sardonyx. Zodiacal sign Virgo. Flower Poppy.

SEPTEMBER: Natal stone Chrysolite. Guardian angel Tsuriel. His talismanic gem Jacinth. Special apostle Lebbeus Thaddeus. His gem Chrysoprase. Zodiacal sign Libra. Flower Morning-glory.

OCTOBER: Natal stone Beryl. Guardian angel Bariel. His talismanic gem Agate. Special apostle Simon. (Zelotes.) His gem Jacinth. Zodiacal sign Scorpio. Flower Hops.

NOVEMBER: Natal stone Topaz. Guardian angel Adnachiel. His talismanic gem Amethyst. Special apostle Matthias. His gem Amethyst. Zodiacal sign Sagittarius. Flower Chrysanthemum.

DECEMBER: Natal stone Ruby. Guardian angel Humiel. His talismanic gem Beryl. Special apostle Paul. His gem Sapphire. Zodiacal sign Capricornus. Flower Holly.

A HINDU LIST OF GEMS OF THE MONTHS: April – Diamond. May – Emerald. June – Pearl. July – Sapphire. August – Ruby. September – Zircon. October. Coral. November – Cat’s-eye. December – Topaz. January – Serpent-stone. February – Chandrakanta. March – The gold Siva-linga.

GEMS FOR THE DAYS OF THE WEEK

Sunday – Sunstone. Monday – Moonstone. Tuesday – Star sapphire. Wednesday – Star ruby. Thursday – Cat’s-eye. Friday – Alexandrite. Saturday – Labradorite.

GEMS OF THE HOURS

Hours of the Day: 7 Chrysolite. 8 Amethyst. 9 Kunzite. 10 Sapphire. 11 Garnet. 12 Diamond. 1 Jacinth. 2 Emerald. 3 Beryl. 4 Topaz. 5 Ruby. 6 Opal.

Hours of the Night: 7 Sardonyx. 8 Chalcedony. 9 Jade. 10 Jasper. 11 Loadstone. 12 Onyx. 1 Morion. 2 Hematite. 3 Malachite. 4 Lapis-lazuli. 5 Turquoise. 6 Tourmaline

1 Paper. 2 Calico. 3 Linen. 4 Silk. 5 Wood. 6 Candy. 7 Floral. 8 Leather. 9 Straw. 10 Tin. 12 Agate. 13 Moonstone. 14 Moss agate. 15 Rock-crystal, glass. 16 Topaz. 17 Amethyst. 18 Garnet. 19 Hyacinth. 20 China. 23 Sapphire. 25 Silver. 26 Star. sapphire, blue. 30 Pearl. 35 Coral. 39 Cat’s-eye. 40 Ruby. 45 Alexandrite. 50 Gold. 52 Star ruby. 55 Emerald. 60 Diamond, yellow. 65 Star sapphire, gray. 67 Star sapphire, purple. 75. Diamond Amethyst.

WEDDING ANNIVERSARIES

MineralsList of gemstones by species

There are over 300 types of minerals that have been used as gemstones. These include:

A - B

Actinolite, Nephrite (var.), Adamite, Aegirine, Afghanite, Agrellite, Alunite, Amblygonite, Analcime, Anatase, Andalusite, Chiastolite, Andesine, Anglesite, Anhydrite, Annabergite, Antigorite, Bowenite, Apatite, Apophyllite, Aragonite, Arfvedsonite, Astrophyllite, Atacamite, Austinite, Axinite group: Ferroaxinite, Magnesioaxinite, Manganaxinite, Tinzenite, Azurmalachite, Azurite, Baryte, Bastnaesite, Bayldonite, Benitoite. Beryl subgroup: Aquamarine, Maxixe, Emerald, Goshenite, Golden beryl, Heliodor, Morganite, Red beryl, Beryllonite, Beudantite, Biotite, Boleite, Boracite, Bornite, Brazilianite, Brookite, Brucite, Bustamite, Bytownite, Blue Lace Agate, Blue Topaz, Bumble bee jasper

C - F

Calcite, Manganocalcite (var.), Caledonite, Cancrinite, Vishnevite, Carletonite, Carnallite, Carnelian, Cassiterite, Cavansite, Celestite, (celestine), Cerussite, Chabazite, Chalcopyrite, Chambersite, Charlesite, Charoite, Childrenite, Chondrodite, Chryso eryl, Alexandrite (var.), Cymophane, Chromite, Chrysocolla, Chrysotile, Cinnabar, Clinochlore, Clinohumite, Clinozoisite, Clintonite, Cordierite, Iolite (var.), Cornwallite, Corundum, Ruby (var.), Sapphire (var.), Padparadscha, Covellite, Creedite, Cryolite, Cuprite, Danburite, Datolite, Descloizite, Diamond, Bort, Diaspor, Diopside, Dioptase, Dolomite, Dumortierite, Elbaite, Emerald, Trapiche emerald (var.), Enstatite, Bronzite, Hypersthene, Eosphorite, Epidote, Piemontite, Erythrite, Esperite, Ettringite, Euclase, Eudialyte, Fayalite, Ferroaxinite, Feldspar subgroup:, Andesine, Albite, Anorthite, Anorthoclase, Amazonite, Bytownite, Celsian, Labradorite, Microcline, Moonstone, Adularia (var.), Rainbow (var.), Orthoclase, Sanidine, Sunstone, Fluorapatite, Fluorapophyllite, Fluorite, Forsterite

G - L

Gahnite, Garnet group:, Pyralspite, Almandine, Pyrope, Spessartine, Ugrandite, Andradite, Demantoid, Melanite, Topazolite, Grossular, Hessonite, Hydrogrossular, Tsavorite, Uvarovite, Almandine-Pyrope, Rhodolite, Andradite-Grossular, Grandite (Mali Garnet), Pyrope-Almandine-Spessartine, Malaia garnet, Pyrope-Spessartine, \Umbalite, Gaspeite, Gaylussite, Gibbsite, Glaucophane, Goethite, Goosecreekite, Grandidierite, Gypsum, Gyrolite, Halite, Hambergite, Hanksite, Hardystonite, Hauyne, Hematite, Hemimorphite, Herderite, Hexagonite, Hibonite, Hiddenite, 

Hodgkinsonite, Howlite, Humite, Iolite, Jade, Jadeite, Chloromelanite, Nephrite, Jasper, Jeremejevite, Kainite, Kornerupine, Kutnohorite, Kurnakovite, Kyanite, Langbeinite, Lawsonite, Lazurite, Legrandite, Lepidolite, Leucite, Leucophanite, Linarite, Lizardite, Londonite, Ludlamite

M - Q

Magnesite, Malachite, Marialite-Meionite, Wernerite (var.), Mimetite, Moissanite, Mottramite, Muscovite, Fuchsite (var.), Musgravite, Narsarsukite, Natrolite, Nepheline, Neptunite, Nickeline, Nuummite, Olivine, Opal, Painite, Papagoite, Pargasite, Pectolite, Larimar, Lemurian Seed Crystal, Peridot, Periclase, Petalite (castorite), Pezzottaite, Phenakite, Phlogopite, Phosgenite, Phosphophyllite, Phosphosiderite, Piemontite, Pietersite, Plumbogummite, Pollucite, Polyhalite, Poudretteite, Prehnite, Prismatine, Proustite, Pumpellyite, Chlorastrolite (var.), Purpurite, Pyrite, Pyrargyrite, Pyromorphite, Pyrrhotite, Quartz, Amethyst (var.), Ametrine (var.), Chalcedony (var.), Agate, Iris Agate, Onyx,, Sardonyx, Bloodstone, (Heliotrope), Carnelian, Chrome Chalcedony, Chrysoprase, Dendritic Agate, Moss Agate, Fire agate (Iridescent var.), Jasper, Petrified Wood, Sard, Citrine (var.), Druzy (var.), Flint (var.), Milky quartz (var.)

Prasiolite (var.), Radiolarite (var.), Rose quartz (var.), Rock crystal (var.), Smoky quartz (var.)

R - Z

Rhodizite, Rhodochrosite, Richterite, Riebeckite, Crocidolite (var.), Rosasite, Rutile, Ruby, Scapolite, Scheelite, Schizolite, Scolecite, Scorodite, Selenite, Sellaite, Senarmontite, Sérandite, Seraphinite, Serendibite, Serpentine, subgroup, Antigorite, Bowenite, Chrysotile, Lizardite, Stichtite, Shattuckite, Shigaite, Shortite, Shungite, Siderite, Sillimanite, Sinhalite, Smithsonite, Sodalite, Hackmanite (var.), Sperrylite, Spessartite, Spinel, Ceylonite (var.), Spodumene, Hiddenite (var.), Kunzite (var.), Triphane (var.), Stichtite, Staurolite, Sulfur, Stolzite, Sugilite, Bustamite (var.), Richterite (var.), Sylvite, Taaffeite, Tantalite, Thomsonite, Thaumasite, Tinaksite, Titanite (sphene)

Topaz Tourmaline subgroup:

Achroite (var.), Chrome (var.), Dravite, Elbaite, Fluor-liddicoatite, Indicolite, Olenite, Paraiba, (var.), Rossmanite, Rubellite (var.), Tremolite, Hexagonite (var.), Tugtupite, Turquoise, Vanadinite, Variscite, Väyrynenite, Vesuvianite (idocrase), Californite (var.), Villiaumite, Vlasovite, Wavellite, Weloganite, Willemite, Wulfenite, Xonotlite, Zektzerite, Zeolites, Analcite, Apophyllite, Chabazite, Goosecreekite, Natrolite, Stellerite, Thomsonite, Zincite, Zinnwaldite, Zircon, Jacinth (var.), Zoisite, Tanzanite (var.), Thulite (var.)