Yes.
You can upload your jewelry items to RapNet for them to only feed through to your Instant Inventory jewelry feed and not be displayed on RapNet.
This is called Own Stock for Instant Inventory.
This article explains how to upload either a single or multiple jewelry items to own stock.
Upload a single jewelry item to Own Stock
If the jewelry item is already listed on RapNet:
Go to Manage My Jewelry > Find the item you want to add to your 'Own Stock'.
Edit > Scroll down to the bottom of the page >
Visibility > Tick Own Stock for Instant Inventory
Save
Upload multiple jewelry items to Own Stock
Prepare your jewelry inventory file, refer to this article for support
Instant Inventory > Jewelry dashboard > View and Edit
Click Own Stock > Upload Own Stock