Sapphires, with an hardness of 9 on the Moh's scale, topped only by moissanites and diamonds, is one of the most valuable and wearable of all gemstones and an excellent choice for
engagement and wedding rings. They are one of my favorite stone to work with since they come in beautiful colors and are durable for all types of jewelry.

Engagement rings and wedding bands with sapphires and diamond or moissanite accents
The beautiful World of Sapphire Colors
Sapphires can be found in a variety of rainbow colors from the most known blues, to greens, yellows, pinks, red, purples and colorless white sapphires. White sapphires are a great alternative to more expensive white diamonds but usually not as sparkly as a diamond, a more understated gem.
Blue is the most sought after color for a sapphire. With colors ranging from inky blue to azure, there is a blue for everyone. The best and most valuable color for a blue sapphire is not the dark inky blue but a mid-toned hue. The the vibrant “cornflower” hue that is most prized when it comes to blue sapphires.
Cornflower Blue Sapphire Engagement Ring
I also love Montana Sapphires. Montana sapphires are mined in the state of Montana, USA. They are also known as the "Native American Sapphire". Montana Sapphires are available in every imaginable color of the rainbow but most commonly come in green to blue shades. Large Montana sapphires are a rarity and can demand high prices.
A collection of rings with Montana Sapphires
Sapphire – in all its rainbow of colors – is the gem given to those born in September or to those born under the sign of Aquarius. Read more about sapphire as a birthstone in this blog post.
Shop Sapphire birthstone rings,jewelry and gifts

Lab created sapphires:
Lab created sapphires are a great alternative to mined sapphires. Duplicating nature's environment, a lab created sapphire grown over time with identical physical, chemical and optical properties to those found in nature.

Dahlia engagement ring with lab grow round sapphire
Major sources for sapphires:
Australia, Cambodia, East Africa, India, Kashmir, Madagascar, Myanmar, Sri Lanka, Thailand, United States
White sapphire rings are available with genuine or lab created sapphires.
Care for your sapphire:
Sapphires are rated “excellent” for everyday wear. Due to their Moh's hardness of 9 they are very scratch resistant but can be scratched by moissanites and diamonds. Avoid exposure to heat and contact with chemicals.
Clean sapphires regularly as any soap scum residue can quickly makes them look dull and lifeless. To clean, gently scrub with a soft toothbrush and a solution of mild dish soap and warm water, rinse well and dry with a lint free cloth. Or clean in an at-home ultrasonic unit. More jewelry care info is available here.

Custom made Fair Trade Sapphire from Malawi set in Bezel Engagement Ring
Sapphire Enhancements:
Most sapphires have been heated to improve their color and sometimes also clarity. Heating is a permanent enhancement, as lasting as the gemstone itself. Heated sapphires can be re-cut and re-polished if needed without affecting it's color hue.
There are also un-enhanced natural sapphires available like the pictured sapphire in the semi-bezel ring below.

Sapphire Grades/ Clarity:
Some sapphire suppliers use a grading that is similar to diamond grading when it comes to clarity/inclusions of the gem (VVS, VS, SI). But more commonly sapphires are graded on a letter scale (B, A, AA) which takes the color saturation, the stones clarity and it's cut and polish into consideration. Grading varies a bit from supplier to supplier and whats an A for one could be a B for another. Grading is always somewhat subjective.
Here a letter grading used by one of my main suppliers for many blue sapphires in commercial standard cuts (non-fair trade sapphires only). The grading for fair trade sapphires I offer is slightly different as colors of sapphires vary based on mining location of gemstones and include more fancy colors like yellow, green, teals and various shades of blues.

Commercial |
Commercial quality; variation in color; included |
|
Dark Denim |
Natural, untreated, medium slightly greenish blue; eye clean to slight imperfections; good cut; good polish |
|
Denim |
Natural, untreated, slightly greenish blue; eye clean to slight imperfections; good cut; good polish |
|
Light Denim |
Natural, untreated, light slightly greenish blue; eye clean to slight imperfections; good cut; good polish |
|
A |
Medium to dark navy, little or no color zoning; slightly included; good brilliance; good cut; good polish |
|
AA |
Medium navy to royal blue; eye clean; good brilliance; good cut; good polish |
|
AAA |
Medium navy to royal blue; eye clean; good brilliance; excellent cut; excellent polish |
|
B |
Dark navy, little or no color zoning; slightly included; good cut |
|
Ceylon-A |
Medium light to medium blue, little or no color zoning; good cut; good polish |
|
Ceylon-AA |
Medium to medium dark blue, little or no color zoning; good cut; good polish |
|
Bright Blue Fine |
Medium navy blue; eye clean; excellent brilliance; excellent machine cut |
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Not all grades are available for each size and cut of blue sapphire.
The genuine white sapphires I use are usually graded AA (unless otherwise noted).
AA grading : near colorless (may be very slightly yellow, grey or blue); eye clean; good brilliance; good cut; good polish.
Three Stone Prong Set Oval Sapphire Tressa Engagement Ring with Pear-shaped White Sapphire Accents