The Shattered Star consists of seven shards, each attuned to a different school of Thassilonian magic, and each crafted from a different skymetal. Each also bears its own unique curse that can be countered by affixing a specific type of ioun stone. The shards are linked in sequence, with each shard pointing the way to one of that shard’s oppositional school, as defined by Thassilon’s schools of magic. In this way, you can use the shards themselves as a road map to the next shard—but bear in mind that whoever possesses the final shard, the shard of sloth, may well be able to use that shard to find their way back around to the first shard. My notes indicate that the curse of that final shard might be enough to counteract the compulsion to seek out the next in the sequence, though, so that should grant some level of safety—if indeed that final shard is in someone’s possession and not hidden away in some long-forgotten vault.
In any event, I’ve learned the sequence of the remaining five shards, along with their associated ioun stone, skymetal, and rumored powers—those shards are as follows:
Shard of Lust: Associated with enchantment magic; made of a djezet alloy; pink and green sphere ioun stone; allows limited mind control and enhances ability to react to sudden danger.
Shard of Gluttony: Associated with necromancy magic; made of inubrix; pink rhomboid ioun stone; increases ability to withstand damage and grants the power to absorb the health of foes.
Shard of Envy: Associated with abjuration magic; made of noqual; dusty rose prism ioun stone; enhances defenses and the dispelling of magic.
Shard of Wrath: Associated with evocation magic; made of siccatite; deep red sphere ioun stone; allows the creation of bursts of fire and enhances weapon damage.
Shard of Sloth: Associated with conjuration magic; made of abysium; incandescent blue sphere ioun stone; allows the summoning of monstrous minions and provides insight and focus to spellcasting. 
