I found an article (link) about engagement rings that I found interesting. While the survey wasn't academically done, it did survey 3,500 people about their opinions about engagement rings.

It has come up a few times that some reds think that women believe engagements rings should cost over $10,000 and is a frivolous thing all women expect. Interestingly enough, most men and women thing the ring should be cheaper, less than $2,500. It is more men (under 45 years old) than women that want to more expensive rings. Only 5% of women want a ring over $10,000, whereas 9% of men want it. I think the biggest takeaway is that most people, men and women, want cheaper engagement rings. Some women want the finest jewelry, and some men want to dress up their woman like a prize camel. I suppose this data implies that latter are more common, which is counterintuitive.

When it comes to gemstones, diamonds are the most popular by far, with 65% of people preferring them. Twice as many women than men (8% versus 4%) wanted a ring that was just a band, and 6% of women wanted no ring at all. I'm not sure if 6% is a small or large number for that. I count myself among that group, but many women do seem to be gaga over the idea of an engagement ring. Though most people wanted diamonds on the ring, diamond size was actually not that important of a factor. Only 8% of men and 6% of women thought that diamond size was the most important feature. Noteworthy that while men were split between ring design, diamond quality, and craftsmanship being most important, women more readily agreed that ring design was the most important thing.

Men were over twice as likely to want the proposal to be in front of a crowd (7% versus 3%), though a private proposal was still preferred by both.

The last thing I want to note is how often men and women were in agreement. They both agreed that a diamond was the preferred stone (67% versus 65%), a private proposal was best (66% versus 68%), fathers should be asked for permission (56% versus 61%), rings should be cheap (54% versus 44%), and that the proposal should be a surprise (60% versus 65%). For as disharmonious as many on here make relationships out to be, it seems like men and women are on the same page with engagement rings.