Sphene (Titanite) Value
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
As with many gemstones, color, clarity, and carat are the most important value factors, followed by the skill and artistry shown in cutting. A preference exists for lighter tones, especially yellows, light oranges, and greens, which best exhibit sphene’s magnificent dispersion.
Chrome sphene is the most valuable type. The chrome sphene from Baja California is the color of fine emerald and very rare, especially if clean and larger than 1 carat. Brazilian yellow gem material has a sleepy look and isn’t as bright as that from Baja. Some of the largest and most spectacular green gems have been cut from Indian material.
Sphene is usually included and rarely even eye clean.
Size is definitely a premium characteristic with this species.
In general, specimens with reasonably good clarity, strong and attractive body color, and at least some display of dispersion command the best prices.