Had ideas last night for this specific thing so updated the site with this info:

Bonding
Bonding in Sola is very similar to getting married in our world. It involves getting a ring for your lover and to ask them if they'll become forever mates with you. They'd then be on the same ring finger as well, or could be made into an earring, but it's most common with the hand instead. There may or may not be ceremonies, though ceremonies can be very similar to weddings. The whole idea was created by humans, but any humanoid can be a part of it.

Rings
Where bonding rings differ from wedding rings is that they are shown plain and "empty". If the partner accepts the want to bond, they will then schedule a time to see a gem specialist to have their rings designed to be matching and have a specific gem attached showing their kind of love. This way it's easier to see who is bonded to whom. The specialist is the one that talks to the couple to see what their gem stone will be.
The different gem stones are: Amethyst, Garnet, Ruby, Sapphire, Emerald, and Diamond. For a higher price they can be made to be "flawless", but this isn't a need. There is also a custom option, which is also more expensive if the pair decide on a gem that's not on the list and isn't chosen by the specialist.
There usually are markings carved into the blank spaces on the rings as well, making them more unique.

The rings are made out of a dark colored rock to better show off the gem(s).

Gems are either all around the ring or there's one large stone attached. It's more popular to have them embedded all around the ring.
Rings with more than one gem are considered "impure" and looked down upon by most societies, as it could mean there's more than just two people in the same relationship.

Gem meanings:
Amethyst - Strong Love
Garnet - Special Love
Ruby - Warm Love
Sapphire - Calm Love
Emerald - Rich Love
Diamond - Pure Love

Prices
Plain rings are cheap, only being $20 to get.
Gem prices are all the same besides the custom ones. They are rather expensive as well, so to some it could be seen as a cash grab.
To get a ring fitted with a single, large gem it would be $5,000.
To get a ring with several smaller gems, it would be $2,000 per gem added.
Getting the ring carved with specific, delicate designs it would be an extra $1,000.
Custom gems range from $500-$10,000 depending on the type, with the same extra price for carvings.

Pre-made rings are considered in poor taste and not "real love", since they didn't go through the process of seeing which gem fit them most. They are at least way cheaper at being around $500.

Ceremonies
Traditional ceremonies deal with the pairing bringing their family and friends together for a large feast and celebration. The couple may give a small speech, but it is not needed. However, ceremonies can be done however the couple wants, either with their whole family, select people, or just themselves. There is no need for someone to make it official (outside of religion), as they have made it official themselves.
There also doesn't have to be a ceremony at all. Just the show of love and having the rings completed is all that's needed.

In Religion
Several religions take bonding very seriously and only feel that once a straight couple is bonded is when they can actually procreate. If they are not bonded it can be seen as a sin. There is usually a person who does in fact make it official for them, and is required in these strict families.



Fun fact: the gems are based off of the Skyrim gems that you can get in game, as well as the "flawless" title of some of them. The initial idea sprang up because of needing to get 3 flawless amethysts for an Argonian, and it was built from there. This is a special homage to Skyrim, so that it's not confused with Steven Universe' characters.