When shopping for an engagement ring you might want to consider the following:
As regards sapphire vs diamond: they are very similar, sapphire is the next hardest stone to diamond, it is very sparkling and shiny.
Sapphires come in many pastel colors that make them perfect for engagement rings including light pink, peach, lavender, champagne, white etc. And they are more affordable compared to diamonds!
Peach sapphires seem to be on top of bridal fashion pyramid now. Because peach sapphires are very hard to get, there is a trend to substitute them with morganites. Although morganites are similar in color, they are much softer and might be damaged and become opaque in the long run.
It is important to know that morganites are 7-10 times cheaper than sapphires and sell for just $100 per carat in North America. Thus, for a someone who wants to invest in engagement ring it might not be the best choice.