PENTLANDITE
Sometimes cut into cabochons for collectors; brilliant metallic luster.
Ontario lb. 1.00-3.00
PERIDOT, see OLIVINE PERISTERITE, See FELDSPAR PERTHITE, See FELDSPAR PETALITE
Rare pegmatite mineral; colorless to pink; sometimes facetable from clear
areas in colorless crystals from New South Wales; fairly hard, brittle; inclusions
common; collectors’ item only.
New South Wales, facet grade, colorless, 2-8 ct. ct. .85-2.00
South West Africa, massive pink lb. 4.00
Rhodesia, massive pink lb. 1.50
PETOSKEY STONE, See CALCITE PHENAKITE
Hard, colorless pegmatite mineral of considerable rarity; clear crystals some¬times cuttable to faceted gems of 5-10 ct. but usual sizes much less; inclusions common; collectors’ gem only.
Brazil, facet-grade crystals to 10 gm. gm. 2.50-10.00
Urals, colorless facet-grade crystals to 5 gm., gm. 2.50-5.00
I’HOSPHOPHYLLITE
Beautiful pale blue-green soft phosphate mineral found in cuttable crystals only in one Bolivian tin deposit; cleavable, fragile, difficult to process; very rare; collectors’ gem only.
Bolivia, facet grade to 2 gm. ct. 2.00-4.00
PIEDMONTITE, see EPIDOTE POLLUCITE
Colorless to faintly straw-yellow, often with white inclusions; occurs as clear areas in formless grains; medium-hard, brittle; collectors’ gem only.
Maine, facet grade fragments to 10 ct. ct. 1.00-1.50
Connecticut, facet grade fragments to 15 ct. ct. 1.00-2.00
PRASE, See QUARTZ PRASIOLITE, See QUARTZ PREHNITE
Abundant in some lavas as crusts lining cavities; various shades of green, yel¬low, brown; rarely thick enough or colorful enough to provide good cabochon material; unusually translucent kinds are facetable; hard and tough but mainly cut for collectors.
New Jersey, fine green, cabochon grade lb 4.00-10.00
Australia, pale green, cabochon grade lb. 3.00-3.50
Scotland, pale greenish-yellow, facet grade oz. .50-1.00
PROUSTITE
Rare silver mineral of beautiful intense ruby-red color but very soft and diffi¬cult to polish; practically all facetable material comes from old specimens from Chanarcillo, Chile; collectors’ gem only; surface tarnishes in a matter of months.
Facet grade, 2-20 ct. ° ‘ ct. 2.00-5.00
PSILOMELANE, See QUARTZ
PUMPELLYITE (Chlorastrolite)
Only the variety chlorastrolite is used for cabochon gems; it forms compact gray-green nodules in lavas and seldom exceeds S/^” diameter; highest-quality nodules accept a glass-like polish and display a pattern of small dark green to pale grayish-green chatoyant patches; rare in sizes over i/£”; soft, mainly cut for collectors.
Michigan, spot-polished to show quality ea. 1.00-10.00
PYRITE
Solid crystals capable of being faceted or cabochoned into gems of brilliant metallic luster and pleasing brass-yellow hue; soft, brittle; collectors’ gem only.
Various localities, crystals oz. .25
lb. 2.00
PYROPE, See GARNET PYROXMANGITE
A pink manganese mineral sometimes cut into very small faceted gems; from one locality in Japan only; very rare; collectors’ gem only.