Scintillating jewels

What are these guys used for? I know the ones with fervor mod are worth quite a few HR.

Maybe for a merc? I run a resist/IAS jewel in one of my merc's helmets. I don't know what specific meta builds use these particular jewels if that's what you're asking.

Scintillating is worth almost as much resistance as an

Um in armor, and fervor is 75% of the IAS a

Shael would give you when socketed in a weapon. Maybe people like scintillating jewels of [suffix] in order to squeeze as much stat as they can into the socket.

Neither scintillating nor fervor can roll on a rare jewel - magic only.

+15% @ in a Scintiillating jewel is the same in armor as an

Um provides.
Usecase on Self-wield Infinity Novasorc:
Socketing

Skin of the Vipermagi with a 15% @ Scintillating Jewel of Truth (7% fhr) / of Knowledge (+9 Energy) / of Honor (+4 Replenish Life) / of Hope (+20 Life)

A plain scintillating jewel (no suffix) is the same as an

Um rune (if max roll), like Blubbalutsch says. With 15% increased attack speed, it's very valuable and also very useful for any attack-speed based builds. There aren't many other valuable/usable suffixes though - there's a few like of ease (lower requirements), of truth (FHR), and the stat (str/dex) suffixes that are useful. Better than an

Um rune in a unique/set armor/

Helm.

actually, I think plain not perfect jewel has value range from 1

Perfect Amethyst to 3

Perfect Amethyst. (11-14)
As cheaper choice compare to

Um.
Some sorc need this to socket in weapon before level 50.Some fancy choice will use this over Spirit

Crystal Sword. ( staff )

Above 50, some

Teleport char need this to socket in

Wizardspike to ensure safety but it will need perfect and something okay in jewel.