Gold is a is a precious metal with the chemical element symbol Au. It is a bright, slightly orange-yellow, dense, and soft metal. Gold is a relatively rare element that has been used for coins, jewelry, and works of art throughout history. Gold is the most malleable of all metals. It can be made into a single-atom width wire. Gold often occurs as nuggets, veins, and river deposits. Because pure (24k) gold is soft, it’s usually alloyed with other metals for use in jewelry making. It makes it harder and more durable. Alloys with lower karat ratings, such as, 22k, 18k, 14k, and 10k, contain higher percentages of copper, silver, palladium or other metals.

The gold proportion of alloys is measured by karat (k). Pure gold is designated as 24 karat (24/24 parts gold) and abbreviated 24k. There are different gold alloys used in jewelry with 18 karat (75% pure gold), 14 karat (58% pure gold), and 10 karat (41.7% pure gold) being common. In the United States and many other countries, 10K gold (10 parts gold and 14 parts other alloys) is the lowest level of purity that can be legally be marketed and sold using the word “gold.” Others seen are 9k (37.5% gold) and 22k (91.70% gold).

24 Karat Gold
24k gold is the purest and is 99.9% yellow gold. It is the shiniest, yellowest, and most expensive type of gold. Pure gold is hypoallergenic and safe to wear if you have sensitive skin. It also has a high resistance to tarnish and corrosion. 24 karat gold is soft and not ideal for jewelry because it wears out easily.

Common 24 Karat Gold Stamp Marks:
Gold (pure gold)
24 Karat or 24K (24/24 parts gold)
999 (999/1000 parts, or 99.9% gold)

18 Karat Gold
18k gold consists of 75% pure gold and 25% other metals such as silver, copper, and zinc. It is much stronger and more durable than 24k gold and is used in a wide variety of jewelry. 18k gold doesn’t have the same intense yellow color of pure gold. Nickel can cause skin irritation. If the 18k gold alloy contains nickel, it is so low as to be a concern for most people, even those with sensitive skin.

Common 18 Karat Gold Stamp Marks:
18 Karat or 18K (18/24 parts gold)
750 (meaning 750/1000 parts, or 75% gold)

14 Karat Gold
14k gold is the most popular type of gold karatage sold in the United States. It is made from 58.3% pure gold and 41.7% other metals. 14k gold isn’t as bright as 18k, but it’s stronger and less expensive. Allergic reactions to nickel in 14k gold are uncommon.

Common 14 Karat Gold Stamp Marks:
14 Karat or 14K (meaning 14/24 parts gold)
583 (meaning 583/1000 parts, or 58.3% gold)

10 Karat Gold
Containing 41.7% pure gold, 10k gold is the minimum that jewelry can legally be sold as gold in the United States. 10k gold is durable, but its low purity gives it a paler yellow color. For some, this makes it a less popular gold alloy for special types of jewelry, such as wedding rings. Nickel in 10k gold jewelry is more likely to cause problems for those with nickel allergies, since it often has a higher nickel content.

Common 10 Karat Gold Stamp Marks:
10 Karat or 10K (meaning 10/24 parts gold)
417 (meaning 417/1000 parts, or 41.7% gold)

9K is considered real gold in other parts of the world and is the lowest permitted gold purity sold in the UK and Europe. 9K is 9 parts pure gold and 15 parts other metals. In other parts of the world Karat may be spelled Carat.

White Gold

White gold is an alloy of yellow gold and white metals, and sometimes also copper. The less gold and copper content in the metal alloy, the more white it appears. White gold jewelry is usually plated with rhodium, which makes it even whiter. White gold is usually formed from one of two different alloys:

Palladium white gold is a mixture of gold, palladium, and sometimes silver. Palladium is a hypoallergenic precious metal that’s rarer than gold. Common alloy percentages:

18K White Gold: 75% Gold, 0-10% Silver, & 15-25% Palladium
14K White Gold: 58.3% Gold, 28-35% Silver, & 8-14% Palladium
10K White Gold: 41.7% Gold, 46-48% Silver, & 7-11% Palladium

Nickel white gold is not hypoallergenic. It consists of gold, nickel, copper, and zinc. This form of gold is more affordable than palladium white gold. Common alloy percentages:

18K White Gold: 75% Gold, 17-19% Nickel, 4-6% Zinc, & 2-3% Copper
14K White Gold: 58.3% Gold, 7-9% Nickel, 6-8% Zinc, & 18-20% Copper
10K White Gold: 41.7% Gold, 16-18% Nickel, 11-13% Zinc, & 29-31% Copper

Rose Gold

Rose gold first came into wider use in the late 1800s, after it was introduced to the Russian Imperial court by Carl Fabergé. Rose gold is made from gold, copper, and silver. Copper is what gives rose gold its pinkish color. Most rose gold alloys are either 18k or 14k. 18k rose gold is shinier but has a paler rose color. 14k contains more copper and is less bright, but has a deeper rose color. Common alloy percentages:

18K Rose Gold: 75% Gold, 22-23% Copper, & 2-3% Silver
14K Rose Gold: 58.3% Gold, 31-33% Copper, & 8-10% Silver
10K Rose Gold: 41.7% Gold, 37-39% Copper, & 19-21% Silver

Need a gift? Parkville Jewelers can provide a gift in any price range. Pick something by their favorite color or by individual or family birthstones. Many gifts for events and for special interests. If we don’t have it, we can probably make it or order it for you.

Birthstones:

January – Garnet
February – Amethyst
March – Aquamarine
April – Diamond
May – Emerald
June – Pearl, Alexandrite , Moonstone
July – Ruby
August – Peridot
September – Sapphire
October – Opal, Tourmaline
November – Topaz, Citrine
December – Zircon, Turquoise

Wedding Anniversaries:

1st – Gold Jewelry or Clocks
2nd – Garnet Jewelry
3rd – Pearls, Crystal Jewelry or Leather (Leather Bracelet or Wallet)
4th – Blue Topaz or Flowers (Flower Jewelry)
5th – Sapphire or Wood (Wood in Jewelry, Pens, Boxes & Watch Boxes)
6th – Amethyst Jewelry
7th – Onyx or Copper Jewelry
8th – Tourmaline Jewelry
9th – Lapis Lazuli Jewelry
10th – Diamond Jewelry
11th – Turquoise Jewelry
12th – Alexandrite or Jade Jewelry
13th – Citrine Jewelry
14th – Opal Jewelry
15th – Watches or Ruby Jewelry or Crystal Items
16th – Peridot Jewelry
17th – Watches or Carnelian Jewelry
18th – Cat’s eye or Alexandrite Jewelry
19th – Aquamarine Jewelry
20th – Emerald Jewelry or Platinum
21st – Iolite Jewelry
22nd – Spinel Jewelry
23rd – Topaz Jewelry
24th – Tanzanite Jewelry
25th – Silver Jubilee
30th – Pearl Jubilee
35th – Emerald Jewelry
40th – Ruby Jewelry
45th – Sapphire Jewelry
50th – Golden Jubilee
We can order or make any of these or pick something we already have.

Favorite Colors:

See Gemstone Colors

Events:

Weddings
Gifts for Wedding Attendants
Baptisms
Confirmations
Baby Showers
Graduations
Anniversaries
Work Gifts
Add a Coin with a Special Date to a Coin Bezel
ETC…

Lost and Broken Items:

Repair a family heirloom
Remake a favorite piece of jewelry that was lost
Take gems from an old item and make something new with it
We do in-store repairs for jewelry that has been broken

Jewelry, Keepsake Boxes & Figurines for:

Hobbies
Activities
Animals
Travel Locations
Sport Teams
We can order or make any of these or pick something we already have.

Engraving:

Jewelry
Picture Frames
Glassware
Metal Cups
Ornaments
Watches
Plaques
Lighters
Money Clips
ETC…

Jewelry by Zodiac Symbols:

Aquarius – Black Spinel
Pisces — Garnet
Aries — Emerald
Taurus — Fire Opal
Gemini – Peridot
Cancer — Aquamarine
Leo — Citrine
Virgo – Orange Garnet
Libra — Chrysoprase
Scorpio — Zircon
Sagittarius — Amethyst
Capricorn — Sapphire

Colors of Common Gemstones:

Clear:
Diamond, Moissanite, White Sapphire, White Spinel
White:
Moonstone, Opal, Pearl
Purple:
Amethyst, Iolite, Sapphire, Spinel, Tanzanite
Purple-Blue:
Iolite, Sapphire, Spinel, Tanzanite
Red-Purple:
Amethyst, Rhodolite Garnet, Ruby, Topaz, Rubellite Tourmaline, Alexandrite (incandescent light)
Red:
Ruby, Garnet, Spinel, Chrysoberyl, Topaz, Friedelite
Pink:
Pink Tourmaline, Kunzite, Rose Quartz, Spinel, Beryl, Pearl, Moissanite, Topaz, Sapphire
Peach:
Morganite, Garnet
Orange-Red:
Topaz, Citrine, Garnet, Sapphire, Friedelite
Orange:
Topaz, Citrine, Sapphire, Fire Opal, Spessartite Garnet, Spinel, Chalcedony, Sunstone, Zircon
Yellow-Orange:
Citrine, Amber, Topaz, Sapphire, Fire Opal, Chrysoberyl, Spinel, Zircon
Yellow:
Citrine, Diamond, Topaz, Lemon Quartz, Sapphire, Chrysoberyl, Spinel
Yellow-Green:
Peridot, Chrysoberyl, Tsavorite Garnet
Green:
Emerald, Tsavorite Garnet, Tourmaline, Sapphire, Jade, Malachite, Chrysoprase, Alexandrite (daylight)
Blue-Green:
Tourmaline, Topaz, Zircon, Sapphire
Blue:
Sapphire, Topaz, Aquamarine, Lapis, Turquoise, Zircon, Diamond, Spinel, Tourmaline
Brown:
Chrysoberyl, Spinel, Topaz, Garnet, Zircon, Tourmaline, Smokey Quartz, Tiger’s-Eye, Chalcedony
Black:
Onyx, Sapphire, Spinel, Smokey Quartz, Pearl
Multi Colored:
Agate, Alexandrite, Ametrine, Bloodstone, Chrysocolla, Jade, Jasper, Lapis, Opal, Rhodonite, Sunstone, Topaz, Tourmaline, Turquoise

Round (Faceted, Cabochon & Rose Cut)
Oval (Faceted, Cabochon & Rose Cut)
Emerald (Faceted & Cabochon) The most popular of the step cuts
Cushion (Faceted & Cabochon) They have a square shape with rounded edges
Marquise (Faceted & Cabochon) They have pointed ends and are curved on the sides
Pear (Faceted & Cabochon) The have a rounded edge tapering to a point
Trillion & Triangle (Faceted & Cabochon) Trillion cuts have slightly rounded sides & triangles have straight
Princess & Square (Faceted, Cabochon & Rose Cut)
Baguette Thin and elongated with corners with some straight and some that are tapered on one end
Radiant They are usually elongated and have beveled corners
Asscher They are a step cut stone that has an emerald or square shape with cut corners
Heart (Faceted & Cabochon)

The Three Main Gem Cutting Styles

Brilliant Cut – Brilliant cuts consist of triangular and kite-shaped facets that spread from the center of the gem outward. They give off the most light dispersion of any cut.

Step Cut – Step cuts consist of rectangular facets that descend down in steps. Step cuts include emerald and baguette cuts. They show off the stone’s color and clarity. They are generally not as brilliant, but they often appear larger than than other shapes of of the same carat weight.

Mixed Cuts – Mixed cuts combine the brilliant and step cut styles. They have brilliant facets on the crown and step facets on the pavilion, or vice versa. Mixed cuts may even combine cabbing and faceting techniques.

Other Gem Cutting Styles

Cabochon Cut – Cabochons gems are polished into domes. Certain gems, such as opal and moonstone, better display visual effects such as play of color and asterism (star effect). In faceted gems, these effects would be less visible. Some stones may be cut into cabochons because they are a lower quality or too opaque for faceting. Cabochon stones emphasize their color and luster instead of their brilliance. Softer gem materials may also receive cabochon cuts. Opal, Turquoise, Moonstone, Jade, and Onyx are usually Cabochons.

Rose Cut – The rose cut dates back to the 16th century. The rose cut has a round, cabbed flat base and a faceted top.

Checkerboard Cut – In a checkerboard cut, the gem is cut with square facets, so its crown resembles a checkerboard. This cut is sometimes used on translucent stones.

The Gemological Institute of America (GIA) was founded in 1931. GIA created the 4Cs (Color, Clarity, Cut and Carat Weight) as a universal method for establishing the quality of any diamond, anywhere in the world. Now diamond quality can be described in a universal language and diamond customers can know exactly what they are buying.

Color Scale:
In 1953, GIA introduced the D-to-Z color scale for grading the color of diamonds from colorless to light yellow. The letter “D” was chosen for the top grade (colorless).

Clarity Scale:
The GIA Clarity Scale today has six categories ranging from Flawless to Included and contains 11 specific grades. A gemological microscope is used for clarity grading to plot the inclusions and blemishes in all diamonds when a GIA Diamond Grading Report is requested.

Cut Scale:
The GIA Cut Scale ranges from Excellent to Poor. It tells how successfully a diamond interacts with light to deliver the brilliance, fire, and brightness of the diamond. It also assesses the overall cut quality, taking into account such features as proportions, table size, polish and symmetry.

Excellent
Very Good
Good
Fair
Poor

Carat Weight:
The carat weight has been used in the gem trade since antiquity, but the weights differed between locations. In 1907, the use of the metric carat began. The carat is subdivided into fractions or decimals. Small diamonds are weighed in points and 0.01 carats (ct) equals 1 point. Small brilliants with a weight of .07 – .15 carats are called Melees.

(Appoximate sizes for round diamonds)

Can you tell the difference between them?
The difference between a laboratory-grown diamond and natural diamond can be determined using verification instruments. Laboratory-grown are produced in weeks, so they have specific growth-related patterns that can be detected.

Diamond Creation
Natural diamond formation took place millions of years ago under high pressure and heat and the diamonds came toward the surface in limited areas through volcanic activity.

The process to make laboratory-grown diamonds requires the generation of temperatures close to 20% of the temperature of the Sun’s surface. It begins with a small piece of natural diamond. Most laboratory-grown manufacturing occurs in China and India.

Diamond Values
In 2016, a 1.5 carat laboratory-grown diamond cost $10,600 and in early 2023, it decreased to $2,445. From 2016 to 2022, the price of a 1.5 carat laboratory-grown has decreased by over 75% in some diamonds.

Natural diamond prices have also fluctuated. Over the last 25 years, they have appreciated in price by approximately 3% on average each year.

Diamond Grading
The terms used in reports for laboratory-grown diamonds for color and clarity are different. Instead of the D to Z color grades used for natural diamonds, broader category terms are used: Colorless, Near-Colorless, Faint, Very Light and Light. The natural diamond reports have abbreviated clarity grades from If to I3, while lab-grown again use broader terms, such as, Very Slightly Included and Slightly Included.

Natural Diamonds
Under the Kimberley Process mandated by the United Nations and the World Trade Organization, the rough diamond trade is strictly regulated to ensure it is conflict-free. The natural diamond industry is accelerating its traceability initiatives and using technology to bring transparency to its supply chains.

Global natural diamond recovery peaked in 2005 and has decreased by over 30% in the last 16 years.

The diamond industry protects the biodiversity of an area 4 times larger in size than the land they use. It supports the livelihoods of 10 million people. Up to 80% of the rough diamond value can remain with local communities (local purchasing, employment benefits, social programs, infrastructure investment, and taxes).

Lab Diamonds

Any organization selling a laboratory-grown diamond is legally required to disclose it is man-made.

People alter almost all gems for use in jewelry by cutting and polishing them after they are found. There are also several other treatments that may be done to enhance their appearance.

Heat Treatment

It’s the exposure of a gem to high temperatures to alter its color and/or clarity. The heating of gemstones often happens in the countries where they were found. They do not need to be declared according to The World Jewellery Confederation CIBJO guidelines. Heat treatments of these gemstones is considered permanent under normal handling conditions. The most commonly encountered heat-treated gems include:
Amethyst – Heating can remove brownish inclusions in some amethysts or lighten the color of overly dark stones.
Aquamarine – Many aquamarines are naturally a blue–green color. Heating can remove the greenish color to produce a bluer appearance.
Citrine – Some forms of amethyst can be heated and turned into citrine.
Ruby – Heating can remove a purplish color and make the ruby more of a red color. Silk inclusions can also be removed to make a gem look lighter and more transparent.
Sapphire – Heating can intensify the blue color in sapphires and can also remove silk inclusions to make it appear more transparent.
Heating of rubies and sapphires can also cause recrystallization of the silk inclusions to make them more prominent. This allows the cabochon cut gemstone to have stronger asterism, which is a reflecting star effect.
Tanzanite – Heating tanzanite at low temperatures can remove the brownish color to produce a stronger purplish-blue color.
Topaz – Heating yellowish pink topaz sometimes removes the yellow color to show more of the pink color. Heating is also used to control the color of blue topaz. Colorless topaz that is irradiated followed by heating results in a blue color.
Tourmaline – Sometimes heat treating can cause a dark green color to become lighter and it can also affect the color of other tourmalines.
Zircon – Some reddish brown zircons are heated to produce other colors, including an intense blue.

High Pressure High Temperature Treatment (HPHT)

Heating of a diamond to high temperatures under high pressure can remove or change its color. Heating can remove or lessen a yellow or brown color so the gem becomes more colorless. Other types of diamonds may be changed from brown to yellow, orange-yellow, yellow-green, or to blue colors by this process. Only a qualified gem-testing laboratory can confirm the treatment. It is occasionally encountered in colorless diamonds, but more often in some colored diamonds. HPHT treatments are considered stable and permanent for normal jewelry wear and no special care needed.

Irradiation

It is the exposure of a gem to radiation to change its color. This is sometimes followed by a heat treatment to further modify the color. It is also known as a combination treatment. Blue topaz, diamond, and quartz tend to have very stable colors, if not exposed to high temperatures. There is no special care requirements for most irradiated gems. The most commonly encountered gems include:
Beryl – Some varieties of beryl can be irradiated to deepen or change the color. The color tends to fade upon exposure to bright light.
Diamond – Neutron and electron radiation are the most common forms and it is possible to produce green, blue, deep yellow, orange, pink, and red diamonds. It is often combined with a secondary step of heating to achieve additional colors. Naturally occurring strong colors (green, red, blue, purple, and yellow) are rare and very expensive. Strong colors in diamonds should be considered likely altered. Whether a colored diamond is a natural color or treated color requires examination by an experienced gem-testing laboratory.
Quartz – Some varieties of quartz can be irradiated to produce amethyst. In some quartz, heating after irradiation results in a green color.
Sapphires – There are naturally occurring orange sapphires, but in some stones, a bright orange color is produced from a natural pale yellow color. The color in these is not stable and fades upon exposure to bright light.
Topaz – Colors of natural topaz are rarely vivid. Colorless topaz can be subjected to radiation to change its color. Along with heat treatment, strong blue colors can be achieved. Irradiation is frequently encountered in topaz.

Impregnation

The surface of a porous gemstone is soaked with a polymer, resin, wax, or plastic to make it stronger and to improve its appearance. The most commonly encountered gemstones are opaque and they include turquoise, lapis, jadeite, nephrite, amazonite, rhodochrosite, and tiger’s-eye. Due to the melting point of these materials, it can be damaged by heat. A jeweler’s torch should not be used because it can damage the stone. The stone would need to be removed and reset when the piece requires this type of work. It is frequently seen and in most cases a qualified gemologist can identify the treatment.

Bleaching

It’s a chemical used to alter or reduce the color of a porous gem. Jadeite jade, pearls, chalcedony, and tiger’s eye quartz may be bleached to lighten their color. It is frequently encountered in pearls and jadeite.

Dyeing

It is adding a colored dye into porous or fractured gem to change its color. Pearls, turquoise, lapis, nephrite jade, chalcedony, quartz, emerald, and ruby may be dyed. A qualified gemologist can detect dyed gems in most cases. They are frequently encountered for colored pearls and occasionally for most gems. When it is known that gem has been dyed, be careful to keep them from chemicals, such as acetone or alcohol, which could dissolve the dyes. Also, keep them away from long periods of sunlight, which could cause the color to fade.

Amber – It is fossilized resin. Because it starts as a sticky tree resin, it sometimes contains animal and plant material as inclusions. Amber usually is found as yellow-orange-brown, but it also occurs in a range of colors.
Pearl – It is produced within the soft tissue of a living shelled mollusk. Pearls usually are seen as white, but also come in other colors, such as pink, silver, golden, green, blue, and black.

Rock Families:

Only a few gemstones belong to the rock family.

Igneous – Granite is an igneous rock.
Sedimentary – Many gemstone minerals are found in sedimentary rock (Beryl, Opal, Quartz, Turquoise, Malachite, Azurite, Chrysoprase, and Chrysocolla).
Metamorphic – Lapis is 25-40% lazurite and several other minerals, so it is considered a rock. The color is blue, violet, or greenish blue with streaks. Marble is also a metamorphic rock. Connemara Marble is a green colored marble.
Meteorites and Tektites – Moldavite is formed from a meteorite impact.

Minerals:

Most gemstones are minerals, but only a few minerals are gems. A mineral is a naturally formed solid with a crystalline structure, such as Corundum. A gem is a cut and polished solid piece used in jewelry. Sapphire and Ruby are gemstones made out of the mineral corundum.

Mineral Beryl:
Aquamarine – It is a light to dark blue or blue-green colored gem.
Emerald – It is green colored and is the most precocious gem in the beryl group.
Morganite – A pink to violet or a salmon colored gem.

Mineral Chrysoberyl:
Alexandrite – It is a green colored gem in daylight and red in artificial incandescent light.
Cat’s-Eye – Golden-yellow, green-yellow, green, brown, or red with fine inclusions that produce a silver white line that appears to move in a cabochon cut stone.

Mineral Cordierite:
Iolite – It is usually found as a blue to violet gem, but it also can be brownish.

Mineral Corundum:
Ruby – It is a red colored gem.
Sapphire – It is usually found in blue, but it can be any color, except red.

Mineral Diamond:
Diamond – It is crystallized carbon. Only one in 10,000 diamonds found is considered fancy colored (green, red, blue, purple, or yellow). There are a number of processes used to alter the color of a diamond.

Mineral Feldspar:
Moonstone – Colorless or yellowish with a pale sheen.
Aventurine – It is also called Sunstone and is an orange to red-brown gem with a metallic type shine to it.

Minerals Jadeite and Nephrite:
Jade – Green is the most common color, but it comes in other colors and multi-colored.

Mineral Malachite
Malachite is a copper carbonate hydroxide mineral and is light to black green with light and dark bands.

Mineral Olivine
Peridot – It is a yellow-green colored gem.

Mineral Opal:
White Opal – White or light colored with color play (display of rainbow like hues).
Black Opal – Dark colored (gray, blue or green) with color play.
Boulder Opal – An opal with a dark rock base with color play.
Fire Opal – Orange to red colored gem and usually does not show a play of color.

Mineral Quartz:
Amethyst – A purple or violet colored gem. It is the most highly valued gem in the quartz group.
Ametrine – Combination of the amethyst’s purple and citrine’s yellow to orange.
Chalcedony – A waxy or dull colored stone in bluish, white, gray, green, orange, red-brown, and brown. The bloodstone is dark green with red spots.
Citrine – It is light yellow to dark yellow, and golden orange to golden brown colored gem. Natural citrines are rare and most are heat treated amethysts or smoky quartzes.
Rose Quartz – It is a pink colored gem.
Smoky Quartz – It is smoky gray or brown to black colored.
Cat’s Eye – White, gray, green, yellow, or brown colored. When there are numerous fiber-like inclusions and it is cut as a cabochon, it produce a silver white line.
Tiger’s Eye – Golden yellow and golden brown opaque stone with yellow brown streaks.

Mineral Rhodochrosite:
Rhodochrosite is a manganese carbonate mineral. Raspberry red to pink are the most common colors with light and dark colored steaks.

Mineral Silicate:
Garnet Group – It is not a single species, but is composed of multiple species and varieties. The most common color is red. Gems are also found in green, yellow-green, and orange to red-brown.
Onyx – A silicate mineral formed in bands of chalcedony in alternating colors. Sardonyx is a variant in which the colored bands are sard (shades of red) rather than black. Black onyx is perhaps the most famous variety, but is not as common as onyx with colored bands.
Chalcedony – It is a cryptocrystalline form of silica, composed of very fine intergrowths of quartz and moganite. It is found in blueish, white, gray, and orange red to brown in color.

Mineral Spinel:
Spinel – One of the few gemstones that occurs in every color of the spectrum.

Mineral Spodumene:
Hiddenite – A green-yellow to green colored gem.
Kunzite – It is a pink to purple colored gem.
Triphane – It is a yellow colored gem.

Mineral Topaz:
Topaz – Yellow to orange and light to dark blue are the most common colors. It is also found in red-brown, pink-red, violet, and light green gems.

Mineral Tourmaline:
Tourmaline – Prefaced with a color, such as Pink Tourmaline. It comes in many colors and is also multicolored, such as “watermelon” (reddish pink and green).
Rubellite – A red colored Tourmaline.
Indicolite – It is a blue colored gem.
Paraiba – A bright blue to bright green Elbaite Tourmaline.

Mineral Turquoise:
Turquoise – It is sky blue, blue-green, or apple green colored. It usually has brown, dark gray, or black veins of other minerals through it.

Mineral Zircon:
Zircon – It is usually seen as blue gems. The most natural zircons are yellow, red, or brown. Also found in colorless, orange, violet, and green.

Mineral Zoisite:
Tanzanite – It is a sapphire blue, amethyst, or violet colored gem.

Moissanite is 9.5 on the Mohs’ Hardness Scale. It is a naturally occurring silicon carbide and is very rare in nature. Until the 1950s, there was no other source of moissanite other than what was found in meteorites. Synthetic Moissanite is close to diamond in overall appearance and it has some optical properties exceeding those of diamonds.

Morganite is also called pink beryl. The color is light pink, salmon, to violet. Inclusions and fractures are rare, thus making it more durable than stones like emerald. Morganite is one of the rarest members of the beryl family. Due to the scarcity, especially those of high quality, they tend to be among the most expensive gems per carat. Ones that are deep pink in color tend to be the most valuable. It is 7.5 – 8 on the Mohs’ Hardness Scale.

White Sapphire is 9 on the Mohs’ Hardness Scale. Colorless sapphires are uncommon in nature. They were once used as diamond substitutes in jewelry, but are mostly used as accent stones now.

Topaz in its natural state is colorless and is an 8 on the Mohs’ Hardness Scale. It is one of the hardest naturally occurring minerals. These gems may be known as White Topaz or Clear Topaz.

Colorless Zircon is a 6.5-7.5 on the Mohs’ Hardness Scale. It has a high refractive index and strong dispersion, so it has great brilliance. It is more brittle than the other gemstones listed here.

Natural Cubic Zirconia (CZ) was only discovered in the 1930s. Because natural CZ is so rare, scientists began to work on synthesizing it. They have similar names, but Cubic Zirconia (zirconium oxide) and Zircon (zirconium silicate) are quite different gemstones. Synthetic CZ is an 8 on the Mohs’ Hardness Scale and is a good diamond imitation following the synthetic Moissanite.

In prehistoric times Jade was made into arms and tools because of its hardness.

Jade has been known for 7000 years, but in France in 1863, it was found to consist of two distinct minerals. Jadeite and Nephrite. The term jade is used to describe both.

Jadeite and Nephrite come in green and other colors. It may have a color streak of white. Jadeite has a Moh’s hardness of 6.5 – 7 and Nephrite has a Moh’s hardness of 6 – 6.5.

Jadeite is generally off-white, grayish white, and green. It can also be brown, yellowish brown, orange-yellow, reddish orange, lilac, blue-gray. The most valuable is emerald green. The most frequent color is semitransparent to nearly opaque white. It comes mainly from northern Burma, but also from Japan, Tibet, Guatemala, and California. It has a wide range of values.

Nephrite is more common and found in Australia, Brazil, China, Canada, Russia, Taiwan the U.S. and in small quantities almost everywhere. It is less valued than Jadeite. It is found as opaque and translucent in a less lively green. The color can be dark green to blackish, gray, grayish white, or blue-gray. It may contain brown, yellow brown, or orange streaks of iron oxide.

Indian jade is a whitish pale-green to green aventurine (mainly quartz), but it lacks the properties of true jade. Others similar to jade are Korean jade and Transvaal jade, but are not jade either.