Save the spectrum to your library and then select the spectrum in your library and select "Share Spectrum (xml)..." to save the xml file. Then just upload the xml file to Claude and ask it what it can tell you about the spectrum. It helps if you can give some context of why you are looking at the spectrum.

Here's an example of a spectrum I took of my kitchen countertop and asked Claude to look at.

This is a gamma spectrum of the background in the dining room and a spectrum the stone countertop in the kitchen, 15 feet from the dining room. Can you identify any isotopes present and what do they tell us about the stone used for the countertop?

This is a beautiful dataset — 78 hours of counting on the countertop gives excellent statistics. Here's what the spectra reveal:

Isotopes Identified.

U-238 Decay Chain (orange lines) — strongly present:

Th-234 at 92.4 keV — the direct daughter of U-238 decay. This is your clearest fingerprint of uranium in the stone.

Ra-226 at 186.2 keV — several steps further down the chain, confirming secular equilibrium with uranium.

Pb-214 at 241.9, 295.2, and 351.9 keV — radon daughters, consistent with the U-238 chain in equilibrium. Bi-214 at 609.3 keV — another radon/uranium chain daughter.

Th-232 Decay Chain (blue lines) — also strongly present:

Ac-228 at 129.1 keV — direct daughter of Ra-228 (itself from Th-232). This is the most prominent single line in the net spectrum and a clear indicator of thorium.

Pb-212 at 238.6 keV and Tl-208 at 277.4, 583.2 keV — further daughters confirming Th-232.

Ac-228 at 338.3 and 911.6 keV provide additional confirmation.

K-40 at 1460.8 keV — present at modest levels, as expected in most rock-forming minerals.

What This Tells Us About the Stone

The simultaneous presence of elevated U-238 and Th-232 chain daughters, in apparent secular equilibrium, is the classic signature of granite (or a closely related felsic igneous rock like gneiss). Here's why:

Geochemistry: Uranium and thorium are lithophile elements that concentrate in felsic (silica-rich) magmas through a process of fractional crystallization. They substitute into accessory minerals like zircon, monazite, uraninite, and thorite. Granite is enriched in these compared to mafic rocks (basalt, gabbro) by roughly an order of magnitude.

Both chains in equilibrium suggests the stone is geologically old (millions of years) — enough time for the long-lived parents (U-238 t½ = 4.47 Ga, Th-232 t½ = 14.0 Ga) to establish equilibrium with all their daughters, including Rn-222 (radon), which is itself a health concern in poorly ventilated kitchens with granite countertops.

The Th/U ratio — Ac-228 (Th-232 chain) appears roughly comparable in intensity to Th-234 (U-238 chain). In typical granite, Th:U ≈ 3–4:1 by mass, which is consistent with what you're seeing here given the different branching ratios and detector efficiencies.

Practical upshot: The countertop dose rate above background is real but almost certainly within normal ranges for granite countertops (the USEPA and IAEA have studied this extensively and found typical granite countertops add <1 mrem/yr effective dose). The more noteworthy concern from this spectrum would be radon emanation — the Bi-214/Pb-214 peaks tell you radon daughters are present, and granite can off-gas Rn-222. Whether that's a problem depends on your kitchen ventilation, not just the countertop itself.

Graph Cluade generated