The new mineral fluorapophyllite-(NH4), ideally NH4Ca4(Si8O20)F⋅8H2O, was found at the Vechec andesite quarry located near Vechec village, Vranov nad Topľou Co., Prešov Region, Slovak Republic. It occurs in cavities of quartz–illite–saponite–tobelite xenolith embedded in pyroxene andesite. Fluorapophyllite-(NH4) is associated with calcite, tridymite, pyrite, chabazite-Ca and heulandite-Ca. It forms clusters, aggregates or crystalline crusts consisting of individual, well-developed crystals up to 4 mm in size, exhibiting the forms {110}, {101} and {001}. The mineral is colourless to light pink and translucent with white streak and vitreous to pearly lustre; it is non-fluorescent under ultraviolet radiation. The Mohs hardness is ~4½ to 5, tenacity is brittle, fracture is irregular, and there is perfect cleavage on {001}. The calculated density is 2.325 g cm–3. Fluorapophyllite-(NH4) is optically uniaxial (+) with ω = 1.5414(5) and ɛ = 1.5393(8) (λ = 589 nm). It is non-pleochroic. The empirical formula (based on 29 O + F apfu) is [(NH4)0.55K0.32Na0.07Ca0.06]Σ1.00(Ca4.01Mg0.02)Σ4.03Si7.97O20[F0.84(OH)0.16]Σ1.00⋅8H2O. Fluorapophyllite-(NH4) is tetragonal, space group P4/mnc, a = 8.99336(9) Å, c = 15.7910(3) Å, V = 1277.18(3) Å3 and Z = 2. The seven strongest X-ray powder diffraction lines are [dobs in Å,(I,%)(hkl)]: 7.897(32)(002), 7.812(13)(101), 4.547(14)(103), 3.946(100)(004), 2.985(39)(105), 2.4841(11)(215) and 1.5788(12)(00.10). The crystal structure of fluorapophyllite-(NH4), refined to R1 = 0.0299 for 743 unique (I > 3σI) observed reflections, confirmed that the atomic arrangement is very similar to that of the other members of the apophyllite group. The new mineral is named according to the current nomenclature scheme for apophyllite-group minerals and is an NH4 dominant analogue of fluorapophyllite-(K), fluorapophyllite-(Na) and fluorapophyllite-(Cs).

新的矿物fluorapophyllite-（NH 4），理想的NH 4的Ca 4（SI 8 ö 20）F⋅8H 2 O，发现在Vechec安山岩采石场临近Vechec村，托普拉河畔弗拉诺夫有限公司普雷绍夫州，斯洛伐克。它发生在嵌埋在辉石安山岩中的石英-伊利石-皂石-贝利石异岩中。氟皂石-（NH 4）与方解石，鳞石英，黄铁矿，菱沸石-Ca和赤铁矿-Ca有关。它形成簇状，聚集体或结壳，由单个的，发育良好的晶体组成，最大尺寸为4 mm，表现形式{110}，{101}和{001}。矿物为无色至浅粉红色和半透明，带有白色条纹，玻璃态至珠光光泽。在紫外线辐射下不发荧光。莫氏硬度为〜4½至5，韧度易碎，断裂不规则，在{001}上有完美的解理。计算出的密度为2.325 g cm –3。氟皂石-（NH 4）是光学单轴（+），ω= 1.5414（5）和ɛ= 1.5393（8）（λ= 589 nm）。这是非疏油性的。经验公式（基于29 O + F apfu）为[（NH 4）0.55 K0.32钠0.07钙0.06 ] Σ1.00（钙4.01镁0.02）Σ4.03的Si 7.97 ö 20 [F 0.84（OH）0.16 ] Σ1.00 ⋅8H 2 O. Fluorapophyllite-（NH 4）是正方晶系，空间群P 4 / MNC，一个= 8.99336（9）埃，c ^ = 15.7910（3）A，V = 1277.18（3）3和ž = 2 7最强的X射线粉末衍射线[ d OBS在埃，（一世，％）（hkl）]：7.897（32）（002），7.812（13）（101），4.547（14）（103），3.946（100）（004），2.985（39）（105），2.4841（11）（215） ）和1.5788（12）（00.10）。的fluorapophyllite-的晶体结构（NH 4），精制到- [R 1 = 0.0299为743唯一的（我>3σ我）观察到的反射，证实该原子排列非常类似于鱼眼石组的其他成员的。该新矿物是根据当前的Apalitelite类矿物命名法命名的，是fluapophyllite-（K），fluorapophyllite-（Na）和Fluorapophyllite-（Cs）的NH 4主导类似物。