Glass Box

The Glass Box Index

An owned, daily gemstone price index.

100.0 overall · base 100

measured modeled backbone (illustrative)

The line before the epoch is modeled, not measured — an illustrative baseline from documented assumptions, shown until real daily snapshots accumulate. Every point after the epoch is measured from owned data.

Today's reference baskets

Index	Basket median (per-carat)	Listings

How it's built

Each index tracks the median asking per-carat price of a fixed reference basket, normalized to 100 at the epoch, recomputed daily from ~35,000 owned scraped listings — the same proprietary dataset that powers the app's estimator. Median (not mean) so a few aspirational listings can't drag it; natural stones only; asking prices only.

It is an honest open-data retail index: faithful about movement, deliberately humble about absolute level (retail brands vary ~2×, so the engine serves confidence-tiered ranges, never false precision). A transaction-grade index would need gated wholesale feeds; this is built entirely from data Glass Box owns. Full methodology: glass-box-pricing/INDEX_METHODOLOGY.md.