KYI034 Kyanite Rectangle Cushion 10 x 6 mm 2.20 ct $9.00

KYI035 Kyanite Oval 10 x 7 mm 2.50 ct $10.00

KYI036 Kyanite Oval 9 x 6 mm 1.90 ct $7.75

KYI037 Kyanite Rectangle Cushion 13 x 6 mm 3.25 ct SOLD

KYI038 Kyanite Oval 10 x 6 mm 2.10 ct $8.50

KYI039 Kyanite Oval 12 x 8 mm 4.25 ct $17.00

KYI040 Kyanite Oval 9 x 6 mm 2.20 ct $9.00

KYI025 Kyanite Oval 8 x 6 mm 1.80 ct $7.25

KYI026 Kyanite Oval 8 x 6 mm 1.65 ct SOLD

KYI027 Kyanite Emerald 8 x 6 mm 1.85 ct $7.50

KYI028 Kyanite Emerald 8 x 6 mm 1.60 ct $6.50

KYI029 Kyanite Emerald 8 x 6 mm 1.80 ct $7.25

KYI030 Kyanite Emerald 7 x 5 mm 1.50 ct $6.00

KY10 Kyanite Oval 10 x 7 mm 1.90 ct $3.00

KYI033 Kyanite Oval 9 x 8 mm 3.35 ct SOLD

KYI021 Kyanite Oval 8 x 6 mm 1.40 ct $5.75

KYI022 Kyanite Oval 8 x 6 mm 1.70 ct $7.00

KYI023 Kyanite Oval 8 x 6 mm 1.35 ct $5.50

KYI024 Kyanite Oval 8 x 6 mm 1.50 ct $6.00

KYI031 Kyanite Emerald 7 x 5 mm 1.55 ct $6.25

KY4 Kyanite Emerald 8 x 5 mm 1.50 ct $4.00

KYI032 Kyanite Square 7 x 7 mm 1.95 ct SOLD

KY7 Kyanite Oval 9 x 6 mm 1.40 ct $6.00

KY13 Kyanite Oval 7 x 6 mm 1.40 ct $4.00

KY9 Kyanite Oval 7 x 5 mm .90 ct $3.00

Kyanite is a polymorph with two other minerals: andalusite and sillimanite. A polymorph is a mineral that shares the same chemistry but a different crystal structure with another, or other, minerals.

Since the three minerals form under different conditions of temperature and pressure, they are diagnostic for those conditions.
Kyanite is an attractive mineral that has a near sapphire-like blue color in some especially nice specimens.

Kyanite has a nearly unique characteristic in that it has a wide variation in hardness in the same crystal face. The hardness of kyanite is approximately 4.5 when scratched parallel to the long axis of the crystal and approximately 6.5 when scratched perpendicular to or across the long axis. Other minerals usually have variable hardness on different crystal faces due to a different concentration and orientation of the atoms in the structure. Diamond is another such mineral, a fact gem cutters use to their advantage.