Ascension Shard Level 7

I'm in the process of upgrading my Dorgeshuun Crossbow to Power Level 7. However, after looking at the Wiki, it seems the only way to acquire Level 7 Ascension Shards is from Gold/Silver Umbral Sand reward packs. Is there another way I can do this?

Ascension Shard - RuneScape: Dragonwilds Wiki