Beryls Gemstones

Color

Red: Bixbite, only found in one location in Wah Wah Mountains, Utah, USA

Bright yellow: Heliodor. If yellow becomes deep toward orange: "golden Beryl"

Colorless: Goshenite

Deep blue: only found on one location in Brazil: will quickly loose its color if expoed to daylight

Green: too light to be considered emeralds. Problematic as a green beryl is much cheaper than an emerald but sometimes still sold as one

Clarity

Considering the range of beryls clarity can vary from eye-clean to very included

Cut

Beryls may be cut several different ways, though emerald cut and oval cut gems tend to predominate

Treatment

Color: Heating can take out a secondary color rendering a deeper, more saturated color
Color: Sometimes colorless beryls are irradiated to produce yellow colours. This colour is considered stable. Maxixe beryl is almost always irradiated is often irradiated in a laboratory. Color is not stable. Some colourless and light pink beryl from Minas Gerais is irradiated to produce maxixe beryl
Clarity: colourless oil and resins are sometimes used to hide fissures in red beryl

Care

Beryls are generally quite hardy unless they are strongly includedRed beryls tend to be more like emerald in this respect and may be fragile if the gem has many surface reaching fissures. A dampened, non-abrasive cloth is best used to clean beryl jewelry.
Large beryls with high level of saturation
Rare beryls such as Red beryl
Special effects such as "cat's eye"
Borderline beryls: "is it an emerald or is it a green beryl"

Color

Different varieties: purple is a rare variety from Maine. Blue stones from Brazil with colors rivalling Paraiba tourmaline are most in demand
A light green variety of apatite carries the trade name "asparagus stone"
The recent availability of the neon blue-green variety from Madagascar has gained popularity

 

 

Clarity

Eye clean larger stones are quite common

Cut

Cabochon or creative cut by lapidary artists

Treatment

Color: Most apatites are heat treated to enhance color

Care

Apatites are delicate - especially when subjected to heat, temperature changes, changes in air pressure (such as in an airplane)
Dampened soft fabrics with no abrasive or chemical additives, or a soft bristle toothbrush doused with water
Not recommended to use in rings

Aquamarine Gemstone

Color

Main colors: greenish blue to blue green
Light in tone and transparent
Some milky quality if lots of inclusions
Most collectible colors: aquamarines that have saturated, light blue colours are especially desirable, though a few beryl collectors prefer a slight greenish tinge

Clarity

They frequently possess a vitreous clarity not found in emeralds. For this reason, aquamarines may be fashioned as exceptional clean gems and carvings
Lower grade aquamarines can have a milky appearance if the crystal has a lot of inclusions
a potentially desirable "cat's eye" effect occurs when miniscule, hollow growth tubes form parallel to one another

Cut

Relatively large stones can be cut due to its hardness and relatively large crystals (up to hundreds of carats) without inclusions
Unusually cut gems are also popular, especially in gems that have been fashioned by an important lapidary artist.
Aquamarines and other beryls often lend themselves to sculptures because of their size

Treatment

Consider every aquamarine heat treated
Heat treatment causes them to loose their secondary greenish color and create a more "aquamarine blue" gem
It is generally impossible to gemologically determine whether an aquamarine has been treated or not

Care

Aquamarine can be worn in jewelry under normal use. Larger aquamarines should be worn with care, especially in settings such as rings that can be easily knocked
Cleaning: sudsy water and damp cloth

Most collectible:

Saturated, light blue colours
Gems that have been fashioned by an important lapidary artist or cut in unusual ways
Aquamarines from desirable localities, such as Santa Maria aquamarines from Itabira, in Brazil, are collectible in accordance to their legendary depth-of-colour

Ametrine Gemstone

Color

In ametrine, a unique form of quartz mined from a single locality in Bolivia, the colours are both yellow and purple in areas of zoning

Clarity

Ametrine, just like most crystalline quartzes is often eye-clean

Cut

Ametrine can also be cut to blend the two colors so that the resulting stone is a mix of yellow, purple, and peach tones throughout the stone
Ametrine is most typically faceted in a rectangular shape with a 50/50 pairing of the two colors
Sometimes a checkerboard pattern of facets is added to the top to increase light reflection
Ametrine is also popular among artistic cutters and carvers

Care

Because the bi-coloured ametrine comes from only one mine in the world, it is sometimes collected if the depth of colour and the division of colour is strong, or if it has been skillfully or cleverly carved.

Amethyst Gemstone

Color

Transparent to translucent lilac to purple through bluish purple
A reddish purple colour-shift that is sometimes visible in incandescent light
In ametrine, a unique form of quartz mined from a single locality in Bolivia, the colours are both yellow and purple in areas of zoning. Such gems are sometimes cut in a way that mixes the colours, and at other times to show the division of colours

Clarity

Some amethysts have liquid inclusions containing solids and gases (water bubbles)
Some minerals suchas rutile and hematite can be found in amthyst as well

Cut

Amethyst can be found in many sizes and therefore offered in many different kinds of cuts and carvings
Many famous lapidaries (cutters) work with amethysts to make unusual carvings or cuts, which are also highly prized.
Bi-coloured ametrine has been skillfully or cleverly carved to emphasize the bi colored nature of the stone

Treatment

Amethysts are heat treated to improve an overly dark purple color or to get rid of the smoky color
Many amethysts in the market are synthetic. It is virtually impossible to differentiate the two

Care

Care should be taken not to knock the gem during use, as small fissures or cracks may develop, especially along facet junctions. It can be cleaned with warm, sudsy water or a dampened cloth. Some amethysts may lighten in tone over time upon prolonged exposure to bright light.
Collectors of amethyst look for depth of the purple colour with red flashes if the gem is cut conventionally. Many famous lapidaries (cutters) work with amethysts to make unusual carvings or cuts, which are also highly prized. Because the bi-coloured ametrine comes from only one mine in the world, it is sometimes collected if the depth of colour and the division of colour is strong, or if it has been skillfully or cleverly carved.

Amber Gemstone

Color

May be seen in yellow, orange and brown colours and rarely as blue and green.
Impurities and organic substances cause colours in amber.
Green and blue ambers are so perceived due to strong fluorescence in some amber from the Dominican Republic

Clarity

Amber often possess gas bubbles which vary in size and quantity within each piece. In the space between the bubbles, the resin is clear
The bubble inclusions actually interfere with the passage of light through the amber, resulting in the dilution and variation of color and opaqueness. For example, there are so many bubbles in milky amber, when examined under the microscope, it resembles sea foam – thus causing the solid milky color.

Cut

Most amber is fashioned as cabochons or rounded or free-form beads, and are rarely faceted

Treatment

Heating in oil causes some cloudy amber to clarify, or to produce darker amber colours
Amber is sometimes dyed to add a darker tone to lighter materials
Two factors that affect the color of amber is air and the actual tree source

Care

While rings using amber are used, the user must take special care
Avoid rough handling, heat and chemicals for all amber
They are soft, occasionally brittle, and porous enough to be attacked by acids
Cleaning may be performed using a dampened cloth or a moistened soft bristle toothbrush
Strong colours in amber are considered collector items, as is any amber containing unusual insects. Entomologists seeking to understand a bygone world often collect these amber samples for further study.

Alexandrite Gemstone

Color

The colour of alexandrite appears different depending on the light it is viewed in

Daylight: Yellowish, brownish, greyish or bluish green

Incandescent light: Orangy or brownish red to purplish red

The best stones are sometimes loosely described as "an emerald by day and an amethyst at night"

Clarity

The alexandrite variety contains gems that vary from transparent to semi transparent
In terms of clarity, alexandrite is comparable to ruby.
Clean faceted stones in sizes above one carat are rare and above 2–3 carats are extremely rare
Common inclusions are silk like rutile needles

Cut

alexandrites are found in a variety of shapes and cutting styles. Ovals are cushions are the most common

Treatment

Alexandrite is generally never treated to enhance its color or diminuish the appearance of inclusions

Care

Alexandrite is extremely resilient for use in jewellery and can be worn daily under normal circumstances
Most alexandrite can be cleaned in an ultrasonic cleaner and certainly with a damp cloth and warm soapy water
Alexandrite is one of the world‘s most expensive gems, with prices similar to those fetched by fine ruby or emerald because of their rarity and their exotic, phenomenal qualities. A combination of alexandrite and "cat's eye" is the most desirable.
A premium is placed on gems that contain strong colour change qualities, since with alexandrites a predominantly "muddy" mix of greens, browns and reds tends to be the norm, resulting in a vague colour change.

Daftar Gemstones